Tooth Wear: An Authoritative Reference for Dental Professionals and Students (BDJ Clinician’s Guides) 3030861090, 9783030861094

Citation preview

BDJ Clinician’s Guides

Andrew Eder · Maurice Faigenblum Editors

Tooth Wear An Authoritative Reference for Dental Professionals and Students Third Edition

BDJ Clinician’s Guides

This series enables clinicians at all stages of their careers to remain well informed and up to date on key topics across all fields of clinical dentistry. Each volume is superbly illustrated and provides concise, highly practical guidance and solutions. The authors are recognised experts in the subjects that they address. The BDJ Clinician's Guides are trusted companions, designed to meet the needs of a wide readership. Like the British Dental Journal itself, they offer support for undergraduates and newly qualified, while serving as refreshers for more experienced clinicians. In addition they are valued as excellent learning aids for postgraduate students. The BDJ Clinicians’ Guides are produced in collaboration with the British Dental Association, the UK’s trade union and professional association for dentists. More information about this series at https://link.springer.com/bookseries/15753

Andrew Eder  •  Maurice Faigenblum Editors

Tooth Wear An Authoritative Reference for Dental Professionals and Students Third Edition

Editors Andrew Eder UCL Eastman Dental Institute and Harley Street Dental and Implant Clinic London, UK

Maurice Faigenblum UCL Eastman Dental Institute London, UK

2nd edition: © BDJ Books 2002 ISSN 2523-3327     ISSN 2523-3335 (electronic) ISBN 978-3-030-86109-4    ISBN 978-3-030-86110-0 (eBook) https://doi.org/10.1007/978-3-030-86110-0 © Springer Nature Switzerland AG 2002, 2022 Originally published by BDJ Books, London, 2002 This work is subject to copyright. All rights are reserved by the Publisher, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed. The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. The publisher, the authors and the editors are safe to assume that the advice and information in this book are believed to be true and accurate at the date of publication. Neither the publisher nor the authors or the editors give a warranty, expressed or implied, with respect to the material contained herein or for any errors or omissions that may have been made. The publisher remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. This Springer imprint is published by the registered company Springer Nature Switzerland AG The registered company address is: Gewerbestrasse 11, 6330 Cham, Switzerland

Dedicated with very grateful thanks to Our families, All the contributors, Our teachers, Our colleagues, Our students, And to all our patients for whom we always try to do our very best.

Foreword

In his foreword to the first edition of this acclaimed book in 2000, Sir Ian Gainsford highlighted the problems of tooth wear as being a ‘major challenge’ to our profession. A little over 20 years later, these challenges continue to grow, particularly due to erosive wear across the generations and our increasingly elderly population thankfully keeping their teeth for longer. As a consequence, the profession should welcome the third edition of this authoritative clinical guide for dental professionals and students. Each of the 32 authors is actively involved in clinical research or management of patients presenting with worn teeth. This multidisciplinary group of contributors have drawn upon relevant research complemented by their own clinical experience. The result is a significantly expanded text that is accessible to the entire dental team and covers the problematic presentation and multifactorial aetiology of tooth wear. Various management options are considered, and clinical examples guide the reader through practical approaches to care for patients in an effective and contemporary manner. The emphasis throughout is on diagnosis and prevention as well as minimal intervention wherever appropriate and possible. This book will serve as the recommended text for the first blended learning course on the management of tooth wear developed by the Faculty of Dental Surgery at the Royal College of Surgeons of England. I congratulate the editors and authors for this comprehensive clinical guide that will be invaluable to dental professionals across the globe as they care for increasing numbers of patients with tooth wear. Matthew Garrett Dean, Faculty of Dental Surgery Royal College of Surgeons of England London, UK

vii

Tooth Wear: Editors’ Introduction

Abstract Alongside dental caries and periodontal diseases, tooth wear is an increasingly important area of clinical dentistry. Raising awareness of tooth wear and its early identification, just as all dental professionals would wish to do for all primary dental diseases and particularly oral cancers, are essential aspects of providing effective oral healthcare for our patients. Here, we introduce the latest edition of this multi-­ author textbook on tooth wear.

Introduction Anthropologists have regarded tooth eruption in humans as being genetically predetermined and with us since the beginning of humanity. Its aim, seemingly, is to compensate for natural wear of the incisal edges and occlusal surfaces [1]. However, the types of tooth wear that had remained unchanged since the origins of life have undergone profound changes in a very short space of time. Today’s tribochemical pathological model has replaced the abrasive physiological model of the past [2]. Several synonyms have been used to describe this model. In 1997, Smith et al. made a cogent suggestion that the term ‘Tooth Wear’ should be used exclusively with the aim of drawing the patient’s attention to the potentially irreplaceable destruction of the hard dental tissues [3]. This recognises the essential need to obtain the patient’s cooperation through counselling and monitoring. Another metonym that has been widely used to describe tooth wear is ‘bruxism’. From the perspective of the dental practitioner or patient, bruxism has always been considered the act of nocturnal grinding of the teeth and the resultant damage [4]. However, there is now a view that the bruxism construct has shifted from pathology to a motor activity with possibly even physiological or protective relevance [5]. Thus, it may in fact be a risk or a protective factor for any single individual (with solar radiation being cited as a similar example) [6]. Hence, using ‘harmless behaviour’, ‘risk factor’ and ‘protective factor’ as terms describing the various possible consequences of bruxism ‘is still the best option’ [6].

ix

Tooth Wear: Editors’ Introduction

x

Defining Tooth Wear In the latest Delivering Better Oral Health evidence-based toolkit [7], tooth wear is included in the summary guidance for the first time alongside dental caries, periodontal diseases, oral cancer and behaviour change. In this document, tooth wear is defined as the cumulative loss of mineralised tooth tissue due to chemical and/or mechanical factors with plaque not being involved in the aetiology. Tooth wear is normally multifactorial (Fig. 1) and involves a combination of erosion (chemical loss due to extrinsic or intrinsic acids), attrition (physical loss due to tooth-to-tooth contact) and abrasion (physical loss caused by objects other than teeth) [7]. Abfraction (a tooth wear defect near a gingival margin) is mentioned, but there is a lack of clinical evidence to support this as a separate cause of tooth wear [7]. In the earliest stages, enamel remineralisation may be possible [7]. Once tissue has been lost from a tooth, leading to a change in its shape or form, tooth wear becomes irreversible [7]. Multiple widely accepted descriptors of tooth wear have been used in recent years and include chronological, non-age-related, pathological and accelerated tooth wear [7]. The use of the term ‘Tooth Surface Loss’, which was the title of previous editions, has been superseded by ‘Tooth Wear’ which is internationally recognised [7]. As described by Loomans et al. in the European Consensus Statement of 2017, the age of a patient and the amount of tooth tissue lost together define the tooth wear status of any particular patient [8]. With progression over time, wear may become severe with substantial loss of tooth structure, dentine exposure and significant loss Fig. 1 Common presentations of tooth wear

Erosion resulting in loss of surface anatomical detail and volume of tooth tissue

Abrasion of the softer dentine once the protective enamel has been lost

Attrition, normally of opposing occlusal contacting surfaces, seen here as a result of many years of interdental contact in this elderly patient has resulted in contact points becoming broader contact areas

Tooth Wear: Editors’ Introduction

xi

(≥1/3) of the clinical crown [8]. Tooth wear which is atypical for the age of the patient has been described as pathological tooth wear and can cause pain or discomfort, functional problems or deterioration of the appearance, which, if progressing, may give rise to undesirable complications of increasing complexity [8].

Setting the Scene Tooth wear (Fig. 2) has become a key feature of national dental surveys in England [9, 10]. Within each of these aetiological factors of erosion, attrition and abrasion will be a wide range of possible causes. Most challenging is that these processes are rarely seen in isolation, and identifying the individual causes within a multifactorial aetiology is essential if care strategies are to be successful (Fig. 3). Commonly, one of the aetiological factors will be dominant (Fig. 4). Patients will most often present with problems of altered function or a compromised appearance, but this may be quite a late presentation with symptoms of sensitivity and sharpness of teeth developing sooner. At the more advanced stages of wear, quality of life may also be negatively impacted, and how this can be improved should increasingly be considered as an essential aspect of planning care. Fig. 2  56-year-old male with tooth wear due to erosion, attrition and abrasion

Fig. 3  78-year-old female with tooth wear of multifactorial aetiology

xii

Tooth Wear: Editors’ Introduction

Fig. 4  71-year-old male with attrition as the dominant tooth wear aetiology

Individuals may develop tooth wear at any age. Younger patients may have grown up having significant quantities of fruit juice, whilst adolescents may gravitate toward sweetened carbonated drinks, both on a far too frequent basis. Stomach acid reflux in various forms can present across a multitude of ages, and our elderly, who are thankfully living longer and keeping their teeth longer, may simply see their teeth wearing out after decades of use. As a result, and in contrast to managing caries or periodontal diseases, there is a broad range of care strategies to consider, and these are presented throughout this book. A few overarching principles, however, are clear: • Early professional identification and patient education are key. • Preventive strategies should be put into place expeditiously. • Minimally invasive care is preferable wherever appropriate and possible. Most patients will be cared for by their general dental practitioners, often supported by their dental hygienists, but some patients may require specialist care and others multidisciplinary care. This will be determined by the aetiology and cause as well as the extent and rate of tooth wear. In some patients, progression may be slow and in harmony with what one might expect of their age, often described as chronological wear. In others, it might be considered as being more advanced, often described as pathological or accelerated wear (Fig. 5), based on its impact related to the age of the patient. In patients for whom specific habits exist or who exhibit meticulous oral hygiene regimes, this can result in unusual presentations of severe wear (Fig. 6a–d). Indices such as the Basic Erosive Wear Examination (BEWE) [11] are available to quantify the extent and degree of tooth wear. Whilst incredibly helpful in informing care plans, such indices are at times more suited to epidemiological research. However, being able to transfer historically subjective views to relevant quantifiable recordings is invaluable in protecting patients. This becomes increasingly important as their needs are considered against a mild, moderate and severe matrix of care priorities. Alongside indices, evidence in the form of photographs, study casts and, increasingly, 3D imaging (Fig. 7) is an essential part of the patient’s records and helps to inform management decisions.

Tooth Wear: Editors’ Introduction

xiii

Fig. 5 Pathological localised anterior tooth wear in a 22-year-old female

a

c

b

d

Fig. 6 (a–d) 78-year-old female with meticulous oral hygiene care, including interdental cleaning, resulting in severe root surface abrasion

xiv

Tooth Wear: Editors’ Introduction

Fig. 7  CBCT 3D scan showing significant palatal tooth wear of a maxillary incisor

Challenges Throughout this book, and as highlighted in previous editions, the following three commonly discussed priority areas are considered in depth: • Difficulties in diagnosing tooth wear • Difficulties in controlling tooth wear • Difficulties in restoring worn teeth Having both cared for patients with tooth wear for several decades, the editors wish to add the following thoughts for consideration. The first relates to decision-making and what might influence a move from prevention, education and behaviour management to interventive treatment, albeit in a minimally invasive approach whenever appropriate and possible. The second looks at our ability to turn back the clock for our patients, maintaining satisfactory function and appearance at every step along the way. Bringing these thoughts together into a single additional priority area, we need to identify younger patients at the earliest opportunity who may in the future need an extensive reconstruction at an increased occlusal vertical dimension under the care of a specialist prosthodontist. Figures 8 and 9 highlight these issues and whether early identification, prevention, education and even minimally invasive treatments for younger patients (Fig. 8) might avert the need for many hours of complex treatment for older patients later in life (Fig. 9).

Tooth Wear: Editors’ Introduction

xv

Fig. 8  20-year-old female with anterior incisal tooth wear due to attrition

Fig. 9  58-year-old female with multifactorial generalised tooth wear

Conclusion This book is targeted at all dental professionals, including dental students. When compared to previous editions, this latest version takes us on an enhanced journey from understanding tooth wear, through population health and risk management, the science of saliva and how teeth actually wear through to planning and delivering care as well as maintenance and dealing with restorative failures. A critically important topic once restorative care is under consideration is the availability of inter-occlusal space for predictable outcomes with severe wear often needing to be managed with complex treatment at an increased occlusal vertical dimension. Much of the management section is devoted to space creation and material selection with an emphasis on minimal intervention and additive approaches within any restorative care plan wherever possible.

xvi

Tooth Wear: Editors’ Introduction

Acknowledgement Grateful thanks are given to Dr. Simon Cunnington for permission to use the image in Fig. 7. Andrew Eder UCL Eastman Dental Institute and Harley Street Dental and Implant Clinic London, UK [email protected] Maurice Faigenblum UCL Eastman Dental Institute London, UK [email protected]

References 1. Ainamo A, Ainamo J. The dentition is intended to last a lifetime. Int Dent J 1984;34(2): 87–92. 2. d’Incau E, Couture C, Maureille B. Human tooth wear in the past and the present: tribological mechanisms, scoring systems, dental and skeletal compensations. Arch Oral Biol 2012;57(3):214–29. 3. Smith BGN, Bartlett DW, Robb ND. The prevalence, etiology and management of tooth wear in the United Kingdom. J Prosthet Dent 1997;78:367–72. 4. Teeth grinding—what really happens when you sleep. The London Times; 3 September 2020. 5. Manfredini D, Ahlberg J, Lobbezoo F.  Bruxism definition: past, present and future. What should a prosthodontist know? J Prosthet Dent 2021. Available at: https://doi.org/10.1016/j.prosdent.2021.01.026. 6. Lobbezoo F, Ahlberg J, Aarab G, Manfredini D. Why using ‘harmless behaviour’, ‘risk factor’ and ‘protective factor’ as terms describing the various possible consequences of bruxism is still the best option. J Oral Rehab;2020:001–2. 7. Office for Health Improvement and Disparities, Department of Health and Social Care, NHS England, NHS Improvement. Delivering better oral health: An evidence-based toolkit for prevention, Version 4. London: OHID, DHSC, 2021. [Available from: https://www.gov.uk/government/publications/ delivering-better-oral-health-an-evidence-based-toolkit-for-prevention. 8. Loomans B, Opdam N, Attin T, Bartlett D, Edelhoff D, Frankenberger R, Benic G, Ramseyer S, Wetselaar P, Sterenborg B, Hickel R, Pallesen U, Mehta S, Banerji S, Lussi A, Wilson N.  Severe tooth wear: European Consensus Statement on Management Guidelines. J Adhes Dent 2017;19(2):111–119. https://doi.org/10.3290/j.jad.a38102.

Tooth Wear: Editors’ Introduction

xvii

9. NHS Digital. Adult Dental Health Survey 2009—Summary report and thematic series [NS]. London: The Health and Social Care Information Centre; 2011. https://digital.nhs.uk/data-­a nd-­i nformation/publications/statistical/ adult-­dental-­health-­survey/. 10. NHS Digital. Child Dental Health Survey 2013, England, Wales and Northern Ireland. London: NHS Digital; 2015. https://digital.nhs.uk/data-­and-­ information/publications/statistical/children-­s-­dental-­health-­survey/. 11. Bartlett D, Ganss C, Lussi A. Basic Erosive Wear Examination (BEWE): a new scoring system for scientific and clinical needs. Clin Oral Investig. 2008;12(Suppl. 1):65–8. Published online 2008 Jan 29. https://doi.org/10.1007/ s00784-­007-­0181-­5.

Acknowledgements

Previous editions of ‘Tooth Surface Loss: The Authoritative Reference for Dental Practitioners and Students’ comprised a themed series of articles originally published in the British Dental Journal in 1999 following lectures given to the Alpha Omega London Dental Society in 1995 and 1996. This latest edition has expanded from 14 to 21 chapters. The number of authors, all from the UK and across Europe, has also increased from 13 to 32. Royalties from all editions will continue to be shared equally between the Alpha Omega London Charitable Trust and the British Dental Association Benevolent Fund. We are indebted to all the contributors of this and earlier editions for their dedication as are we to colleagues at the British Dental Journal and Springer Nature. Since embarking on this latest edition about 3 years ago, much of the writing and editing has been completed as the world did its very best to tackle Covid-19. The editors are also incredibly grateful to Professor Richard Ibbetson as one of the co-editors of the previous editions and to Professor Nairn Wilson CBE for his encouragement and helpful comments on the various manuscripts along the way.

xix

Contents

Part I Introduction to Tooth Wear 1

An Overview of Tooth Wear����������������������������������������������������������������������   3 Deepesh Patel and Raelene Sambrook

2

 Tooth Wear and Population Oral Health������������������������������������������������  15 Jenny Gallagher, Jenny Godson, and Rebecca Harris

3

Risk Factors in Tooth Wear����������������������������������������������������������������������  27 Lucy Slater, Andrew Eder, and Nairn H. F. Wilson

4

Saliva and Tooth Wear������������������������������������������������������������������������������  37 Raelene Sambrook

5

 eeding and Eating Disorders: Behaviours That Adversely F Impact Oral Health������������������������������������������������������������������������������������  47 Alex Milosevic and Fatemeh Amir-Rad

6

 Physiology of Erosive Tooth Wear and Relationship with Dentine Hypersensitivity������������������������������������������������������������������  71 Saoirse O’Toole and Owen Addison

7

 Associations Between Tooth Wear and Dental Sleep Disorders: An Overview ����������������������������������������������������������������������������������������������  83 Peter Wetselaar and Frank Lobbezoo

8

 Dento-Legal Considerations in the Management of Patients with Tooth Wear ����������������������������������������������������������������������������������������  93 Len D’Cruz

Part II Management of Tooth Wear 9

 Pragmatic Philosophy of Tooth Wear Management �������������������������� 105 A Bas Loomans and Shamir Mehta

xxi

xxii

Contents

10 Treatment  Planning for Patients with Tooth Wear �������������������������������� 121 Robert Stone 11 Occlusion and Splint Therapy������������������������������������������������������������������ 135 Nicholas Capp and Andrew Eder 12 Tooth  Wear in the Child and Adolescent ������������������������������������������������ 153 Paul Ashley and Kathy Harley 13 Surgical  Crown Lengthening in the Management of Tooth Wear �������������������������������������������������������������������������������������������� 165 Richard Horwitz 14 Orthodontic  Therapy in the Management of Tooth Wear��������������������� 179 Asif Chatoo 15 Adhesive Restorations������������������������������������������������������������������������������� 187 Sophie Watkins, Matthew Jerreat, and James Baker 16 Fixed Prosthodontics��������������������������������������������������������������������������������� 213 Konstantina Dina Dedi 17 Removable Prosthodontics������������������������������������������������������������������������ 231 Kenneth Hemmings 18 Dental  Implants in the Management of Tooth Wear������������������������������ 247 Pranay Sharma and Pratik Sharma 19 Prevention,  Maintenance and Dealing with Failures������������������������������ 277 Judith Wickens Tooth Wear: Future Considerations���������������������������������������������������������������� 295 References ���������������������������������������������������������������������������������������������������������� 303 Index�������������������������������������������������������������������������������������������������������������������� 305

Part I Introduction to Tooth Wear

1

An Overview of Tooth Wear Deepesh Patel and Raelene Sambrook

1.1 Introduction Tooth wear in younger people is on the increase and becoming a growing concern [1]. Between the United Kingdom’s Adult Dental Health Surveys published in 1998 and 2009 there was an increase of tooth wear in young adults (aged 16–24) from 35% to 50%. Similarly, there was an increase in wear from 58% to 68% in 25–34 year old [2]. More recently, a systematic review in 2015 estimated that the prevalence of erosive wear in the permanent teeth of people aged 8–19 years was 30.4% [3]. This provides a worrying concern for dental professionals, as this younger generation of patients will require lifelong preventative management. This commitment is further increased if these patients enter the restorative cycle. There are a number of reasons why we may be seeing this increase in tooth wear in younger patients. Firstly, there is an increased intake of soft drinks and energy drinks in younger age groups [4]. The five most popular energy drinks in the UK have pH values ranging from the lowest of 2.72–3.37 as the highest [5]. Each of these drinks has a pH range below 5.5, the critical pH below which enamel demineralises. In addition to this, there is a growing trend of healthy lifestyles and consumption of fruit drinks, nutrient waters and sports drinks [6] which also have a lower pH. Consumption of these drinks is often under the influence of strong marketing campaigns and social media channels. Whilst tooth wear occurs as a natural process throughout life, physiological tooth wear or normal wear should be differentiated from pathological tooth wear. For D. Patel (*) UCL Eastman Dental Institute, London and Private Practice, Cambridge, UK e-mail: [email protected] R. Sambrook Prosthodontics Unit, UCL Eastman Dental Institute, London, UK e-mail: [email protected] © Springer Nature Switzerland AG 2022 A. Eder, M. Faigenblum (eds.), Tooth Wear, BDJ Clinician’s Guides, https://doi.org/10.1007/978-3-030-86110-0_1

3

4

D. Patel and R. Sambrook

premolars and molars, the physiological rate of wear has been estimated as 25 and 38 μm respectively [7]. In comparison, permanent incisors have been reported to wear at a rate of approximately 18 μm per year [8]. To establish whether the degree of tooth wear is physiological or pathological, the patient’s age should be taken into account. It is deemed pathological tooth wear if the wear is greater than expected for the patient’s age [9]. For example, it may be considered normal for a 70-year-old to have lost 1 mm from the incisal edge of a central incisor [8], yet, this same loss of tooth structure would be pathological if the patient was 20 years old.

1.2 Types of Tooth Wear and Clinical Presentation Pathological tooth wear resulting in severe tooth structure loss is multifactorial and can be classified into four categories: attrition, erosion, abrasion and abfraction.

1.2.1 Attrition Attrition is caused by tooth-to-tooth contact and primarily affects the occlusal and incisal surfaces of teeth. Bruxism is a major cause of attritive tooth wear and is defined as a repetitive jaw-muscle activity characterised by clenching or grinding of the teeth and/or bracing or thrusting of the mandible [10]. It is recognised that bruxism can occur when asleep (sleep bruxism) or when awake (awake bruxism) (Chap. 7). The aetiology of bruxism is unknown, though it is likely to be multifactorial (Table 1.1) [11]. The clinical features commonly presenting are flattening of incisal and occlusal edges where facets can fit together (Fig. 1.1a). Compensatory mechanisms can result in dento-alveolar compensation which maintains intercuspation and tooth contact as teeth wear and become shorter in length. Once the enamel layer has been worn down, dentine may be exposed (Fig. 1.1b). The result is a surface that is more susceptible to further wear. The differential rate of enamel and dentine wear often leaves a cupped-out region.

1.2.2 Erosion Erosion is a major cause of tooth wear [12] and is the result of non-bacterial acids demineralising the enamel and dentine hydroxyapatite structure (Table 1.2). Table 1.1  Factors increasing the risk of bruxism Lower age Female Tobacco Alcohol and caffeine Psychosocial such as stress and anxiety Sleeping disorders such as sleep apnoea Genetics Certain medications

1  An Overview of Tooth Wear

5

a

b

Fig. 1.1 (a) (left): Worn incisal edges and occlusal surfaces but dento-alveolar compensation maintains tooth-to-tooth contact. (b (right)): Loss of enamel exposes the dentine layer Table 1.2  The causes of intrinsic and extrinsic acid erosion Intrinsic causes Gastro-oesophogeal reflux disease (GORD) Anorexia nervosa Bulimia nervosa Chronic alcoholism Rumination Dehydration

Extrinsic causes Carbonated drinks Fruit juices and smoothies Occupational hazards Effervescent vitamin drinks Medication preparations such as oral aspirin and ascorbic acid (vitamin C) Sports such as swimming

The erosive process is dynamic and complex and involves initial surface softening through the loss of calcium and phosphate ions. This results in a surface susceptible to increased damage from abrasive and attritive forces. Whilst early signs of erosion may not be noticed by patients, it can be picked up with good lighting and magnification by a dental health professional. The typical presentation is loss of initial surface texture and some thinning of incisal edges and cusp tips. The cause of erosive tooth wear may be due to an acid source, either intrinsic or extrinsic or in some instances both. A common presentation of intrinsic acid erosion is wearing of the palatal surfaces of the maxillary teeth (Figs.  1.2 and 1.3). The mandibular incisor teeth are generally spared in these cases [13]. Extrinsic erosion can result in thinning of the incisal edges and increased translucency of the incisal edges of maxillary incisors [14] (Fig. 1.3). The buccal and cervical regions may also be affected. The occlusal surfaces may present with cupped out regions around the cusp tips in the earliest stages prior to a more crater like appearance as the lesion advances. Alternatively, erosion of tooth structure may be due to dehydration [15]. In this scenario, there is reduced salivary flow and subsequently reduced buffering capacity [13], rendering the dental hard tissue at risk of softening. For example, medications may result in dehydration. Also, exercise can lead to dehydration and erosion can be exacerbated if dehydration is managed with the consumption of sports drinks. Sports such as swimming can also cause direct erosion to the dentition due to the pH of the water in the swimming pool [16].

6

D. Patel and R. Sambrook

Fig. 1.2  Palatal erosion of teeth as the result of a 28-year-old patient with uncontrolled gastro-­ oesophageal reflux disease (GORD)

Fig. 1.3  Palatal erosion of teeth in a 40-year-old patient following a history of gastro-oesophageal reflux disease (GORD) and a high acidic intake of fruit juice

1.2.3 Abrasion Abrasion is the result of frictional forces on a tooth by an exogenous object. This may be habitual such as the action of overzealous toothbrushing (Fig. 1.4) or biting on hard objects such as pens, pencils and hair clips. Occupational or social factors such as a hairdresser holding hair pins, or a wind instrumentalist are at risk of abrasive tooth wear. Abrasion may also be iatrogenic where improper use of dental materials are not utilised, for example ceramic that is not adequately polished following adjustment [17].

1  An Overview of Tooth Wear

7

Fig. 1.4  Buccal view showing recession and associated abrasion lesions in a 58-year-old patient

Fig. 1.5 Non-carious cervical abfraction lesions with a characteristic V-shape appearance

1.2.4 Abfraction Abfraction lesions were originally defined by Lee and Eakle [18] and described as V-shaped lesions at the cervical margin of teeth subjected to excessive tensile stresses during guiding movements (Fig.  1.5). More recently, the terminology describes these as non-carious cervical lesions where the accepted aetiology is an interplay of multiple factors including stress, abrasion and erosion [19].

1.3 Tooth Wear Indices Whilst the inherent subjective nature of any recording system can limit their use, many indices exist to measure tooth wear and aid in epidemiological data research as well as clinical assessment [20]. The Basic Erosive Wear Index (BEWE) is one

8

D. Patel and R. Sambrook

example [21]. The aim of this tool is to measure, classify and record the severity of erosion. Whilst it has been suggested to be an effective index for screening tooth wear [22], it also has been designed to be very easy to use by the general dental practitioner and follows the principle and format of the Basic Periodontal Exam (BPE). The dentition is divided into sextants with the most severe score recorded. The scoring system is as follows; 0 = no erosive tooth wear, 1 = initial loss of surface texture, 2 = distinct hard tissue loss less than 50% of the surface area and 3 = hard tissue loss more than or equal to 50% of the surface area. A cumulative score is then totalled resulting in a risk level. Although interventional management strategies have been advised based upon this level [23] this should not be regarded as absolute. As there are a multitude of causes that may result in tooth wear, similarly, there will also be several factors that determine which treatment modality is most suited for each individual patient.

1.4 Quality of Life The quality of life is an important consideration when managing patients with tooth wear (Chaps. 5 and 9). In more severe cases, patients will often present with complaints including sensitivity and sharp teeth. However, aesthetic concerns are an increasingly common complaint of patients [24]. The oral health impact profile (OHIP) has been used to measure the quality of life and tooth wear severity. A recent multicentre, international study [25] looked at patients in primary care. They assessed the degree of tooth wear using the BEWE and found that with increasing wear, the quality of life was lower. Likewise, there is further evidence of a close relationship between quality of life and tooth wear where more advanced tooth wear negatively impacts on a person’s psychosocial wellbeing [26]. Furthermore, patients who have pathological tooth wear may also have systemic health problems, such as gastro-oesophageal reflux disease (GORD), depression, anxiety and high stress levels [27]. It is, therefore, imperative that the clinician considers the broader impact of tooth wear on each individual when caring for such patients.

1.5 Management of Patients with Tooth Wear ‘No matter how knowledgeable the physician might be, if he/she is not able to open good communication channels with the patient, he/she may be of no help to the latter’ [28].

Good communication plays a key role in the management of patients with tooth wear. The importance of creating a good patient rapport should not be underestimated. This helps to build a trusting relationship which is beneficial for all concerned. An effective patient-centred approach with good communication results in more effective health-related outcomes for the patient [29]. This process needs to start with the first encounter with the patient.

1  An Overview of Tooth Wear

9

These skills are necessary when taking a history to allow targeted questions to be asked to allow the clinician to extract the necessary information to give insight into the aetiology and diagnosis. Patients are generally more willing to give this information when they feel comfortable in their environment. The principles of managing patients with tooth wear stem from the diagnosis, control of the aetiological factors and caring for the patient in their best interests. It is necessary for patients to undergo a full history and examination with any additional special investigations. This may include radiographs, photographs, a diet history and study casts. It may also be necessary to involve their general medical practitioner should intrinsic causes of acid be suspected. Early signs of tooth wear should be diagnosed by a clinician. This enables the clinician to establish a care plan with the patient. Typically, it will include a preventive element with either monitoring or treatment.

1.6 Preventive Management of Tooth Wear The key to successful management of tooth wear is risk assessment with a strong emphasis on prevention [23]. Tooth wear goes through periods of activity and inactivity. Therefore, the aetiological factors should be identified through a thorough history and examination to allow control. For example, those patients who are parafunctional should be provided with a hard acrylic, full coverage splint to protect the teeth during parafunctional activities (Chap. 11). Caution is also required when providing such splints to patients with erosive tooth wear from gastric reflux, as acidic substances may accumulate within the splint. For many years, fluoride has been considered important for prevention of erosive tooth wear, in addition to identifying and eliminating the erosive source. Fluoride application encourages remineralisation of enamel resulting in fluorapatite formation. This is more stable at a lower pH compared to hydroxyapatite, giving a more resilient enamel surface to acid attack, resulting in less demineralisation [30]. Despite this, fluoride will not prevent erosion in its entirety [31]. There have been a number of alternative remineralising agents developed in the attempt to prevent the progression of erosive tooth wear including fluoride free preparations and bioactive agents (Table 1.3). Table 1.3  Remineralising agents and mode of action Remineralising agent Sodium fluoride (available as 22,600 ppm, 5000 ppm, 2800 ppm, 1450 ppm) Casein Phosphopeptide-Amorphous Calcium Phosphate (CPP-ACP) Stannous fluoride Calcium silicate

Mode of action Encourages fluorapatite formation and a more acid resistant surface [30] Increased availability of calcium and phosphate to encourage remineralisation [32, 33] Tin ions form barrier that attaches to the acquitted pellicle [12] Encourages a hydroxyapatite-like layer to form creating a physical barrier [34]

10

D. Patel and R. Sambrook

The use of agents to promote remineralisation is important in the initial phases of managing a patient with tooth wear, as an adjunct to educating patients and control of the aetiological factors. The purpose is to reduce the ongoing loss of tooth structure. This phase should be continually reviewed and potentially maintained long term.

1.7 Monitoring Tooth Wear During the preventive phase, monitoring tooth wear is essential to assess the rate of progression. The clinician must bear in mind that records provide a single snapshot of the dentition at a given time. Therefore, sequential records are required to give an insight into the rate of progression. This can be done using various techniques such as study casts, the use of a silicone index and intra-oral scanning (Fig. 1.6). Although not 100% accurate, these can give a reference point. As previously described, a number of tooth wear indices have been proposed such as the BEWE. In addition to the subjective nature of these qualitative methods, they are not sufficiently sensitive to accurately monitor the rate of progression which is required to inform clinical management. The use of digital technologies has increased significantly within dentistry. The digitisation of stone casts via a contact scanner has shown promising results in the monitoring and comparison of tooth wear over a 1 year period [35]. More recently, the use of intra-oral scanners is becoming increasingly reliable to monitor the progression of tooth wear, allowing quantitative analysis of a current situation compared to a reference. The sensitivity of the scanner appears to be better for more advanced tooth wear lesions and may not be suitable for detecting the earliest lesions. Furthermore, they require the use of accurate model alignment and specific software that may not yet be commercially available. This constantly evolving technology is encouraging [36].

Fig. 1.6  Intra-oral scan showing early attrition on the mandibular incisors (courtesy of Devonshire House Dental Laboratory)

1  An Overview of Tooth Wear

11

1.8 Restorative Management of Tooth Wear Restorative management of tooth wear may be driven by the patient and can include situations where there may be symptoms or aesthetic concerns. The clinician may also take a leading role when the tooth wear is more advanced and further loss of tooth structure may complicate restorative treatment in the future [23]. Nevertheless, support for minimum intervention strategies for managing tooth wear is well documented [37–39]. Accepted forms of such treatment are generally provided in the most conservative way possible to maximise remaining tooth structure and provide the most predictable outcome [17, 40, 41]. When restorative treatment is provided, this should be carried out using a minimally invasive approach utilising adhesive techniques [42]. The predictability of such methods involves reliance on a good quantity and quality of enamel to provide an ideal substrate for bonding. This can involve composite resin, glass ceramics and precious or non-precious metals. Where a lack of space exists, treatment may need to be carried out using a reorganised approach. Restorative space may be gained by additive or subtractive methods always being as conservative as possible. For example, such patients have been successfully and predictably managed using the Dahl concept [43]. Traditionally, this utilised a removable cobalt chrome anterior bite plane covering the palatal surfaces of the maxillary teeth. Following a period of time, a combination of extrusion and intrusion occurs resulting in the creation of space for restorative materials. It is imperative that patients are forewarned of the time treatment may take for movement to occur, what may need to be done if sufficient movement does not take place within a reasonable timeframe and the need for long term maintenance. Restorative materials are a key consideration. For each patient there will be a trade-off between invasiveness, aesthetics, longevity of the material, time of treatment and cost. For example, composite resin has been used as a direct restorative material in tooth wear cases. A study by Gulamali et al. [44] showed direct composite resin to have a median survival of 5.8 years. The majority of restorations had complications, though these were normally easily managed at the chair-side. A number of other studies have also supported the use of composite resin as a suitable material for the treatment of tooth wear [45, 46].

1.9 How Do We Rationalise Decisions? The decision of when to intervene is a difficult one and a grey area for many clinicians. Initiating restorative treatment commits the patient to a lifetime of restorative care with long term management required, the need for which the patient must be made aware in advance. On the other hand, a prolonged period of monitoring can result in extensive loss of tooth structure with poor enamel and short clinical crowns. In these situations, adhesive dentistry is not as predictable, and crown lengthening

12

D. Patel and R. Sambrook

surgery may be indicated (Chap. 13). The failure of these extensively restored teeth, which may have been reduced further in size by subtractive methods, reduces coronal tooth structure and can result in more catastrophic failure. This may be able to be avoided by earlier, additive and adhesive treatment. Any decisions about management must take into account not only the patient’s wishes but also their best interests. Each patient must be carefully assessed, and care plans tailored to the concerns of both the patient and the clinician. Patients who seek and receive treatment for tooth wear have been shown to have an improved quality of life [47]. Yet, in the same study, patients with moderate to severe tooth wear who had no request for restorative treatment, had no change observed in their quality of life after 1 year. These patients received counselling alongside monitoring of their tooth wear; an essential part of management. It is, therefore, imperative that care plans are made for the patient in the short, medium and longer terms, with the patient being actively engaged in decision making regarding their future care.

1.10 Conclusion Tooth wear is being detected in more people and at a younger age. It is essential that as oral health care providers, we are equipped to diagnose tooth wear as early as possible. The management of tooth wear should be proactive and considered as a journey for the patient, since a reduced quality of life is seen in these patients, particularly when the tooth wear becomes more severe. Educating patients about their oral and dental health is critical as is the importance of prevention which must be a priority to both clinicians and patients, as this will delay or even avoid patients from entering the restorative cycle and the inevitable lifetime of maintenance. It is this comprehensive care plan which incorporates identification, education and prevention that is essential. However, when there is a need to intervene with restorative management, this should be done in a minimally invasive manner using additive and adhesive techniques where possible. Alongside all of this, whatever factors caused the tooth wear in the first place should either be eliminated, or their impact reduced.

References 1. Slater L, Eder A, Wilson N. Worn’ing: tooth wear ahead. Prim Dent J. 2016;5(3):38–42. 2. White DA, Tsakos G, Pitts NB, et al. Adult Dental Health Survey 2009: common oral health conditions and their impact on the population. Br Dent J. 2012;213(11):567–72. 3. Salas MM, Nascimento GG, Huysmans MC, Demarco FF.  Estimated prevalence of erosive tooth wear in permanent teeth of children and adolescents: an epidemiological systematic review and meta-regression analysis. J Dent. 2015;43(1):42–50. 4. Harley K. Tooth wear in the child and the youth. Br Dent J. 1999;186(10):492–6. 5. Clapp O, Morgan MZ, Fairchild RM. The top five selling UK energy drinks: implications for dental and general health. Br Dent J. 2019;226(7):493–7.

1  An Overview of Tooth Wear

13

6. Tahmassebi JF, Duggal MS, Malik-Kotru G, Curzon ME.  Soft drinks and dental health: a review of the current literature. J Dent. 2006;34(1):2–11. 7. Lambrechts P, Braem M, Vuylsteke-Wauters M, Vanherle G.  Quantitative in-vivo wear of human enamel. J Dent Res. 1989;68(12):1752–4. 8. Ray DS, Wiemann AH, Patel PB, et al. Estimation of the rate of tooth wear in permanent incisors: a cross-sectional digital radiographic study. J Oral Rehabil. 2015;42(6):460–6. 9. Hemmings K, Truman A, Shah S, Chauhan R. Tooth wear guidelines for the BSRD part 1: aetiology, diagnosis and prevention. Dent Update. 2018;45(6):483–95. 10. Lobbezoo F, Ahlberg J, Glaros AG, et al. Bruxism defined and graded: an international consensus. J Oral Rehabil. 2013;40(1):2–4. 11. Johansson A, Omar R, Carlsson GE.  Bruxism and prosthetic treatment: a critical review. J Prosthodont Res. 2011;55(3):127–36. 12. Carvalho TS, Colon P, Ganss C, et  al. Consensus report of the European Federation of Conservative Dentistry: erosive tooth wear--diagnosis and management. Clin Oral Investig. 2015;19(7):1557–61. 13. Khan F, Young W.  Toothwear: the ABC of the Worn dentition. West Sussex, UK: Wiley-­ Blackwell; 2011. 14. Taji S, Seow WK.  A literature review of dental erosion in children. Aust Dent J. 2010;55(4):358–67. quiz 475 15. Khan F, Young WG, Daley TJ. Dental erosion and bruxism. A tooth wear analysis from south east Queensland. Aust Dent J. 1998;43(2):117–27. 16. Lussi A, Jaeggi T. Erosion—diagnosis and risk factors. Clin Oral Investig. 2008;12(S1):5–13. 17. Hemmings K, Truman A, Shah S, Chauhan R. Tooth wear guidelines for the BSRD Part 1: Aetiology, diagnosis and prevention. Dental Update. 2018;45:3–10. 18. Lee WC, Eakle WS. Possible role of tensile stress in the etiology of cervical erosive lesions of teeth. J Prosthetic Dent. 1984;52(3):374–80. 19. Soares PV, Grippo JO.  Non-carious cervical lesions and cervical dentin hypersensitivity. Quintessence Publishing; 2017. 20. Lopez-Frias FJ, Castellanos-Cosano L, Martin-Gonzalez J, Llamas-Carreras JM, Segura-Egea JJ. Clinical measurement of tooth wear: tooth wear indices. J Clin Exp Dent. 2012;4(1):e48–53. 21. Bartlett D, Ganss C, Lussi A. Basic Erosive Wear Examination (BEWE): a new scoring system for scientific and clinical needs. Clin Oral Investig. 2008;12(S1):S65–8. 22. Dixon B, Sharif MO, Ahmed F, et  al. Evaluation of the basic erosive wear examination (BEWE) for use in general dental practice. Br Dent J. 2012;213(3):E4. 23. Loomans B, Opdam N, Attin T, et al. Severe tooth wear: European Consensus Statement on Management Guidelines. J Adhes Dent. 2017;19(2):111–9. 24. Wazani BE, Dodd MN, Milosevic A. The signs and symptoms of tooth wear in a referred group of patients. Br Dent J. 2012;213(6):E10. 25. Mehta SB, Loomans BAC, Banerji S, Bronkhorst EM, Bartlett D. An investigation into the impact of tooth wear on the oral health related quality of life amongst adult dental patients in the United Kingdom, Malta and Australia. J Dent. 2020;99:103409. 26. Li MHM, Bernabe E. Tooth wear and quality of life among adults in the United Kingdom. J Dent. 2016;55:48–53. 27. Papagianni CE, van der Meulen MJ, Naeije M, Lobbezoo F. Oral health-related quality of life in patients with tooth wear. J Oral Rehabil. 2013;40(3):185–90. 28. Asnani M. Patient-physician communication. West Indian Med J. 2009;58(4):357–61. 29. Stewart MA.  Effective physician-patient communication and health outcomes: a review. CMAJ. 1995;152(9):1423–33. 30. Lussi A, Hellwig E, Klimek J.  Fluorides—mode of action and recommendations for use. Schweizer Monatsschrift fur Zahnmedizin. 2012;122:1030. 31. Mohammed A, Dusara K. What is the role of topical fluoride application in preventing dental erosion? Evid Based Dent. 2013;14(2):59–62. 32. Rees J, Loyn T, Chadwick B. Pronamel and tooth mousse: an initial assessment of erosion prevention in-vitro. J Dent. 2007;35(4):355–7.

14

D. Patel and R. Sambrook

33. Poggio C, Lombardini M, Colombo M, Bianchi S.  Impact of two toothpastes on repairing enamel erosion produced by a soft drink: an AFM in vitro study. J Dent. 2010;38(11):868–74. 34. Sun Y, Li X, Deng Y, et  al. Mode of action studies on the formation of enamel minerals from a novel toothpaste containing calcium silicate and sodium phosphate salts. J Dent. 2014;42:S30–S8. 35. Ahmed KE, Whitters J, Ju X, et al. Clinical monitoring of tooth wear progression in patients over a period of one year using CAD/CAM. Int J Prosthodont. 2017;30(2):153–5. 36. Michou S, Vannahme C, Ekstrand KR, Benetti AR. Detecting early erosive tooth wear using an intraoral scanner system. J Dent. 2020;100:103445. 37. Bartlett D. A personal perspective and update on erosive tooth wear—10 years on: Part 1— diagnosis and prevention. Br Dent J. 2016;221(3):115–9. 38. Mehta SB, Banerji S, Millar BJ, Suarez-Feito JM. Current concepts on the management of tooth wear: Part 4. An overview of the restorative techniques and dental materials commonly applied for the management of tooth wear. Br Dent J. 2012;212(4):169–77. 39. Bevenius J, Evans S, L’Estrange P. Conservative management of erosion-abrasion: a system for the general practitioner. Aus Dent J. 1994;39(1):4–10. 40. Hemmings K, Truman A, Shah S, Chauhan R. Tooth wear guidelines for the BSRD Part 2: fixed management of tooth wear. Dental Update. 2018;45:11–9. 41. Hemmings K, Truman A, Shah S, Chauhan R. Tooth wear guidelines for the BSRD Part 3: removable management of tooth wear. Dental Update. 2018;45(8):687–96. 42. Bartlett D. A personal perspective and update on erosive tooth wear—10 years on: Part 2— restorative management. Br Dent J. 2016;221(4):167–71. 43. Poyser NJ, Porter RW, Briggs PF, Chana HS, Kelleher MG. The Dahl concept: past, present and future. Br Dent J. 2005;198(11):669–76. quiz 720 44. Gulamali AB, Hemmings KW, Tredwin CJ, Petrie A.  Survival analysis of composite Dahl restorations provided to manage localised anterior tooth wear (ten year follow-up). Br Dent J. 2011;211(4):E9. 45. Milosevic A, Burnside G.  The survival of direct composite restorations in the management of severe tooth wear including attrition and erosion: a prospective 8-year study. J Dent. 2016;44:13–9. 46. Loomans BAC, Kreulen CM, Huijs-Visser H, et al. Clinical performance of full rehabilitations with direct composite in severe tooth wear patients: 3.5 years results. J Dent. 2018;70:97–103. 47. Sterenborg B, Bronkhorst EM, Wetselaar P, et al. The influence of management of tooth wear on oral health-related quality of life. Clin Oral Investig. 2018;22(7):2567–73.

2

Tooth Wear and Population Oral Health Jenny Gallagher, Jenny Godson, and Rebecca Harris

2.1

Introduction to a Public Health Perspective

Healthcare has changed in recent decades to embrace the prevention of oral disease and the promotion of oral health, as part of high-quality disease management. This represents a paradigm shift in healthcare, which is underpinned by research; and, to a certain extent supported by health policies. It also reflects a change in society where expectations of health are changing to manage risk of future disease, not just managing established conditions, together with a recognition by clinicians and researchers that much oral disease is preventable. Oral health in countries such as the United Kingdom has improved greatly over recent decades. As people live longer and patterns of disease change, this means that most adults now retain some, or all, of their teeth into older age. Thus, there are more people and teeth at risk of oral disease. Hence, there is much greater recognition of the need to prevent oral and dental disease and great encouragement for us as health professionals that improvement is possible. It is worth being clear at the outset that a public health population perspective might judge interventions to address tooth wear on a slightly different basis than a clinician judging what might be the best possible approach for an individual patient sitting before them in a dental surgery. This is because wider principles apply,

J. Gallagher (*) Faculty of Dentistry, Oral and Craniofacial Sciences, King’s College London and Public Health England, London, UK e-mail: [email protected] J. Godson Public Health England, London, UK R. Harris Dental Public Health, The University of Liverpool, Liverpool, UK e-mail: [email protected] © Springer Nature Switzerland AG 2022 A. Eder, M. Faigenblum (eds.), Tooth Wear, BDJ Clinician’s Guides, https://doi.org/10.1007/978-3-030-86110-0_2

15

16

J. Gallagher et al.

involving health equity and the distribution of health outcomes within the group or society. Justice and health inequalities are essential considerations in contemporary healthcare, not afterthoughts [1]. Costs and benefits must be weighed, in making decisions on advice and action to serve people most effectively across the population. Such principles apply to preventive advice and health promotion programmes as well as clinical interventions. The consumption of fruit is a very good case in point. Population health advice encourages everyone to eat at least five portions of fresh fruit and non-starchy vegetables a day [2]. For some health-conscious individuals, excessive ingestion of fruit may be a plausible risk factor for tooth wear. However, it is highly likely that such ‘health-conscious’ and ‘preventively minded’ individuals are more likely to visit dental settings for advice and care on a regular basis. While these individuals experiencing high levels of tooth wear may, after careful risk identification, benefit from individualised dietary advice to limit fruit consumption to ensure they eat at least five-a-day (whilst ensuring low acidity of any between meal snacks), this is not beneficial advice for the population at large or patients in general. Messages about fruit consumption must take account of the wider benefits that increasing fruit consumption would have for everyone in society, from being a good source of vitamins and minerals, to providing dietary fibre to maintain a healthy gut and reduce the risk of heart disease, stroke and some types of cancers. Compare this with smoking and tobacco use, where the behaviour has costs to both the individual and society and no health benefits. In this latter instance, the population and individual advice are aligned to recommended avoidance or cessation of tobacco use [3]. We will revisit this issue, having reviewed definitions and the epidemiology of tooth wear, later in this chapter. Tooth wear is the cumulative loss of mineralised tooth substances, which occurs over time (Table  2.1). It is a complex process which may be slow and steady or episodic, affecting both primary and permanent dentitions due to chemical and/or mechanical factors [4, 5]. Tooth wear is largely only a problem for patients when it causes symptoms including aesthetic concerns. It is a concern for clinicians when it is pathological or accelerated [4]; thus, suggesting that the patient is likely to have future symptoms during their lifetime. A decision about whether there is tooth wear present must be judged against a patient’s age, using clinical judgement, and supported by available screening tools [4, 6–9]. Moderate tooth wear in the maxillary anterior teeth in a 12- or 15-year-old would be a cause for concern, whereas in an older adult this would be considered a natural part of ageing. Table 2.1 Definitions Label Tooth wear Erosion Attrition Abrasion

Definition Cumulative loss of mineralised tooth substances Chemical loss/dissolution of the tooth mineral in the absence of plaque, due to exposure to either intrinsic or extrinsic non-bacterial acids Physical loss due to tooth-to-tooth contact Physical loss caused by objects other than teeth, such as a brush or metal object

Sources: Loomans et al. [4]; Shellis and Addy [5]

2  Tooth Wear and Population Oral Health

17

Several indices have been developed to measure and monitor tooth wear [4, 6–9]. There is little evidence of incidence (rate of progress) of tooth wear as most evidence comes from cross-sectional studies, and the type of index used has a significant effect on estimates of prevalence [10].

2.2

Epidemiology of Tooth Wear

National oral health surveys provide an overview of the level of disease at population level. They provide a clearer indication of the level of the problem in the population than local surveys, or surveys of hospital patients, particularly when the latter involve attendees of specialist care; however, they are not without their limitations. Table 2.2 provides an overview of the findings of the latest survey data and survey tools within the United Kingdom.

Table 2.2  Epidemiology of tooth wear in the UK: national surveys Children: primary dentition

Children and young people: permanent dentition

Adults

Tooth wear • 33% of 5-year-olds had evidence of tooth wear on one or more of the buccal surfaces of their primary maxillary incisors, with tooth wear on lingual surfaces more common 57% • Only 4% of 5-year-olds had wear which involved dentine or pulp • 38% of 12 -year-olds and 44% of 15-year-olds had some tooth wear on the lingual surfaces of incisors • Only 2% and 4% respectively had tooth wear involving the dentine or pulp • Tooth wear is more common on lingual surfaces of maxillary central incisors than buccal surfaces, and more common on buccal than lingual surfaces of premolars • 2% had severe wear • 15% had evidence of moderate tooth wear • Moderate wear more common in men (19%) cf women (11%) • Increases with age: 4% 16–24 years cf 44% 75–84 years

Examination notes  The buccal and lingual surfaces of primary •  maxillary incisor teeth were assessed for loss of surface enamel characteristics, and/ or exposure of dentine or pulp • The data were coded as    0 = no surface loss or    1 = some surface loss

• The buccal and lingual surfaces of primary and permanent maxillary incisor teeth and the occlusal surfaces of the first permanent molar teeth were assessed for loss of surface enamel characteristics, and/or exposure of dentine or pulp. permanent maxillary incisors and first permanent molars were examined • The data were coded as    0 = no surface loss or    1 = some surface loss • Only maxillary and mandibular anterior teeth were examined • Three maxillary surfaces (buccal, incisal, and palatal) and the worst mandibular surface of each of the teeth were recorded • Restorations may make teeth unscoreable • Index: simplified tooth wear index

Sources: UK National Oral Health Surveys [11, 12]

18

J. Gallagher et al.

The last cross-sectional Adult Dental Health Survey in 2009 involved people from England, Wales, and Northern Ireland [11], and is due to be updated, for England, in the near future. Its findings provide a helpful overview of the condition, along with the 2013 children’s oral health survey across the same nations [12]. Calibration exercises suggest reliable recording of early tooth wear is particularly difficult. Furthermore, as people live longer and many more retain their natural teeth into older age, the presence of more tooth wear nationally [11], does not necessarily mean there is a public health problem, because it can be a feature of healthy ageing. The 2009 survey found the presence of severe tooth wear involving pulpal exposure or secondary dentine exposure was low at 2% for all dentate adults, whereas 15% had moderate wear [11]. At disease or condition level, this compares with dental caries where 31% had obvious tooth decay in either the crowns or roots of their teeth [11], and 85% of dentate adults had already had a restoration which is an indication of dental caries experience. Almost half (45%) of adults had moderate periodontal (gum) pocketing, exceeding 4mm, whilst 8% had evidence of periodontal disease with pocketing of 6mm and over. Thus, whilst most adults have dental caries experience and periodontal disease, severe and moderate tooth wear are less prevalent in the population. Tooth wear involving dentine or pulp in these index teeth permanent maxillary incisors and first permanent molars of 12- and 15-year-olds is similar to the prevalence reported in the 2003 survey data for these age groups [12]. The primary dentition provides an indication of future risk of dental caries, and there is emerging evidence from longitudinal research in Ireland, that this is the case in relation to tooth wear [13]. There was a significant association between children having dentine-exposed tooth wear in their primary dentition and with tooth wear on the occlusal surfaces of the first permanent molars at 12-years of age [13]. This emphasises the importance of screening for tooth wear by clinicians in younger children to enable early preventive advice and support to be provided. A systematic review and meta-analysis by Salas et al, suggests that 30% of children and young people (8–19 years) have evidence of tooth wear, based on the Tooth Wear Index [10]. This further highlights the importance of early identification of possible tooth wear. A recent population study in the USA found that obesity was positively associated with tooth wear in American adults; which was partially accounted for by the consumption of sugar-sweetened acidic beverages, a common risk factor for both conditions [14]; and the body of evidence is growing [15, 16]. Specialist services are likely to receive referrals of more patients seeking to address their condition because of symptoms. Analysis of hospital referrals suggest that aesthetic concerns were the most prevalent presenting complaint, followed by sensitivity, whilst functional problems and pain were less prevalent [17]. This confirms the importance of generalists picking up disease at an early stage and supporting patients to identify, and manage, their possible risk factors. Several notes of caution should be exercised when looking at the findings of epidemiological cross-sectional surveys. First, the context or sample in which they were conducted may not be representative of the population at large. Second,

2  Tooth Wear and Population Oral Health

19

comparison of their level of disease which is cumulative (and therefore represents evidence of past risk factors) with current behavioural practices may not be valid, because the latter may not be representative of the risks that caused the condition. This highlights the importance of well-designed longitudinal research to provide deeper insights into oral and dental conditions, and the balance of risk and protective practices of populations over time. Furthermore, inequalities in oral health, and timely access to appropriate care, should be considered in relation to tooth wear.

2.3

Risk Factors

Research and clinical practice are highlighting multiple risk factors for tooth wear (Fig. 2.1), including their multifactorial nature [18–21]. Much of the research comes from in vivo and cross-sectional studies; hence, the nature of the evidence needs to be considered. As already stressed, there is a growing body of evidence that acidic drinks (particularly sugar sweetened beverages) are a major dietary risk factor associated with erosive tooth wear [14–16]. Further information on risk factors may be found in Chap. 3.

Fig. 2.1  Multiple risk factors for tooth wear. Sources: Lussi et al. [18, 19]; Ganss et al. [20]; Sovik et al. [21]

Habits

Identify possible risk factors for individal patient's including...

Food

Drinks

Gastrooesophageal factors

Reduced salivary flow

Etc

Medication

Mechanical

20

2.4

J. Gallagher et al.

Population Advice on Tooth Wear

Picking up on the introductory discussion, where we considered how we prevent as much disease as possible, it is very tempting to suggest to the general population that they should avoid or eradicate everything that may potentially contribute to accelerated tooth wear. However, as argued above, this is not necessarily in a patients’ best interest for their general health. The reality is that most people do not have accelerated tooth wear (wear that is not commensurate with that which would be expected for their chronological age); and, most people do not have a healthy-­ enough diet. Furthermore, most people attend dental services, albeit with differing patterns of regularity, when accelerated tooth wear should be picked up at an early stage. This has implications for our health advice for patients in general (general population advice) which may seem counter-intuitive when it differs from advice from those with accelerated tooth wear. Key population messages for oral and general health are outlined in Fig. 2.2. You will see that the advice includes promoting a healthy diet and good oral hygiene with a standard fluoride toothpaste (DBOH 3). It is not appropriate to provide general advice to people to limit their consumption of fresh fruit to prevent the risk of tooth wear. These foods could be considered as a common source of healthy acids. There is clear evidence from national surveys in the UK over recent years that most children and adults do not have a healthy balanced diet including at least five portions of fruit and vegetables each day [4]. Whilst a few individuals may have healthy acids identified as their major risk factor, and end up requiring specialist care, this is not the main dietary risk for tooth wear in general. Given that population level research suggests that the main dietary risk associated with tooth wear is sugarsweetened soft drinks, not fruit, this is covered by general oral health messages. Minimising sugar intake, particularly from sugar-sweetened beverages, is a fundamental aspect of population messaging [3]. In contrast, fruit is a healthy snack and should be encouraged for the general health of children and adults [2]. Promotion of regular dental attendance will be particularly helpful [22, 23], to support early identification and careful management of tooth wear in the future.

2.5

Prevention in Individuals with Tooth Wear

Prevention of oral and dental disease forms an important aspect of contemporary oral healthcare for all dental team members. Tooth wear is a lifelong cumulative process and the importance of recording tooth wear in both the primary and permanent dentitions is emerging [13]. The most important aspect of care, once the presence of accelerated tooth wear has been diagnosed, is to identify all possible sources of risk, chemical and/or mechanical, recognising that acids may be extrinsic or intrinsic, healthy, or unhealthy. Successive chapters will provide deep insights from clinicians and researchers who regularly manage these conditions. However, a summary of the advice is presented in Fig. 2.3, as informed by Delivering Better Oral Health [3].

2  Tooth Wear and Population Oral Health

21

This Photo by Unknown Author is licensed under CC BY-SA

Diet  ensure a healthy balanced diet in line with the Eatwell guide  eat at least five por ons of fruit and vegetables each day  keep sugar below 5% of dietary intake and minimise frequencyof sugar intake  avoid or minimise sugar sweetened drinks (especially carbonated) and fruit juice and/or smoothies (limited to 150ml per day) Oral Hygiene  brush teeth effec vely last thing at night (or before bed me) and at least on one other occasion (for at least 2 minutes)  supported by interdental cleaning Fluoride  using an age-appropriate fluoride toothpaste  pitting out a€er brushing, rather than rinsing with water, to avoid dilu ng the fluoride concentra on Tobacco  avoid all forms of tobacco Alcohol  for people who drink alcohol promote lower risk drinking: 14 Units/week spread over 3+ days with 2 alcohol free days (males/females) Dental aendance  at least once every 12 months for children and young people  at least once every 2 years for adults Sleep  age 18–65 yrs for 7–9 h/night; Age 65+ for 7–8 h/night Exercise  each week, adults should accumulate at least 150 min (2 1/2 h) of moderate  intensity ac vity (e.g. brisk walking or cycling);  or 75 min of vigorous intensity ac vity (e.g. running);  or even shorter dura ons of very vigorous intensity ac vity (such as sprin ng or stair climbing);  or a combina on of moderate, vigorous, and very vigorous intensity ac vity (1 min moderate = 2 min intense) Sources: UK Gov (2016) Eatwell guide (2)

Office for Health Improvement and Disparities et al. (2021) Delivering better oral health: An evidence-based toolkit for prevention. London: GOV.UK (3)

NICE (2004, 2018) Dental Recall Guidance (22, 23) UK Chief Medical Officers’ Alcohol Guidelines Review (24) UK Chief Medical Officers’ Physical Ac vity Guidelines (25)

License to Publish: Open

Government Licence (na onalarchives.gov.uk)

Fig. 2.2  Population health advice for general and oral health

22

J. Gallagher et al.

1. 2. 3. 4. 5.

Screen paents for evidence of tooth wear: children and adults Idenfy possible risk factors: intrinsic, extrinsic, and mechanical Support your paent to manage and reduce their risk factors Consider what protecve acons may be helpful Monitor and review according to risk

License to Publish: Open Government Licence (naonalarchives.gov.uk) Source: Office for Health Improvement and Disparities et al. (2021) Delivering better oral health: An evidence-

based toolkit for prevention. Version 4, 2001. GOV.UK (www.gov.uk) (3)

Fig. 2.3  Managing individual patient risk. Source: delivering better oral health: an evidence-­ based toolkit for prevention V3.1 [3] & V4

Supporting individual patients in risk management may involve close liaison with their medical practitioner and specialist [26]. This provides the opportunity for increasing interprofessional engagement in holistic patient care from conditions such as gastro-oesophageal reflux disease (GORD) through to bulimia and drug abuse. Modifiable risk factors relating to their diet require careful management in partnership with the patient, using contemporary behaviour change approaches. Many of these risk factors, such as frequent consumption of sugar sweetened beverages, will be deleterious to general health as well oral health and the patient can be made aware of the wider health benefits of behaviour change. The principle of swapping to safer drinks should be encouraged, particularly between mealtimes. Whilst it may be rare, what do you do as a clinician with a patient whose major risk factor appears to be an otherwise healthy behaviour (e.g. excessive consumption of fruit juice or fruit)? You have confirmed that there are no intrinsic risk factors such as vomiting, or reflux, and the pattern of disease seems plausible. First, remember fruit juice should only be drunk in small quantities (150 mls) as outlined in the Eatwell guide [2], and may be restricted to mealtimes or replaced by other options. Furthermore, fruit juice only counts as one portion of fruit and vegetables per day. Second, where excessive fruit eating is the risk factor, it will be important to reduce

2  Tooth Wear and Population Oral Health

23

the frequency of acidic fruit intakes, whilst still ensuring a healthy balanced diet. Patients should therefore be encouraged to eat a variety of non-starchy fresh vegetables as part of their daily routine.

2.6

Future Research and Action

Further research evidence is required to support policy and action, particularly from longitudinal studies in relation to the effectiveness of secondary and tertiary prevention of tooth wear and consideration of inequalities. We require a deeper understanding of the causes of accelerated tooth wear and how the condition can best be identified early, risk factors identified, and the condition managed effectively for the benefit of patients. This will be particularly important amongst adolescents and young adults who have most to benefit.

2.7

Conclusion

In summary, as dental caries declines and more people retain their natural teeth into older age, we are increasingly aware of the challenge of tooth wear as an oral condition. Tooth wear naturally increases with age. Although in an ageing population tooth wear is increasingly common, it is a greater concern for individuals with moderate to severe disease, particularly when accelerated, than for the population at large. As accelerated wear may be found at all ages, early detection and careful management are important by all dental team members. Where present, the possible risks (intrinsic and extrinsic) must be explored, identified and managed, in partnership with the patient over time; management which must involve addressing the risk factors appropriately if it is to be successful. Population advice, however, should promote health in general, stressing the importance of regular dental attendance, brushing teeth twice a day (with an age-appropriate fluoride toothpaste) and consuming a healthy balanced diet, including fresh fruit and vegetables. Regular checkups are particularly important to identify accelerated tooth wear at an early stage and support patients in managing this condition effectively. Acknowledgements  The authors which to acknowledge the support of the Delivering Better Oral Health Guideline Development Group for Tooth Wear, convened to support the development of Version 4 (2021) of the evidence-based toolkit for prevention, which informed this chapter. Jenny Gallagher (Clinical Academic lead) and Jenny Godson (Senior responsible officer) are leading the DBOH Version 4 guideline project for former Public Health England and were members of Dental Oversight Group, Guideline Working Group and all Guideline Development Groups. Rebecca Harris Chaired the Guideline Development Group for Tooth Wear.

Useful Resources https://www.gov.uk/government/publications/physical-activity-guidelinesuk-chief-medical-­officers-­report

24

J. Gallagher et al.

https://www.gov.uk/government/publications/alcohol-­c onsumptionadvice-­on-­low-­risk-­drinking https://www.gov.uk/government/publications/the-­eatwell-­guide https://www.gov.uk/government/publications/delivering-better-oral-healthan-evidence-based-toolkit-for-prevention

References 1. DeCamp M, Pomerantz D, Cotts K, Dzeng E, Farber N, Lehmann L, et  al. Ethical issues in the design and implementation of population health programs. J Gen Intern Med. 2018;33(3):370–5. 2. UK Government. The Eatwell Guide London: UK.GOV; 2016. [Available from: https://www. gov.uk/government/publications/the-­eatwell-­guide]. 3. Office for Health Improvement and Disparities, Department of Health and Social Care, NHS England, NHS Improvement. Delivering better oral health: An evidence-based toolkit for prevention, Version 4. London: OHID, DHSC, 2021. [Available from: https:// www.gov.uk/government/publications/delivering-­b etter-­o ral-­h ealth-­a n-­evidence-­b ased­toolkit-­for-­prevention]. 4. Loomans B, Opdam N, Attin T, Bartlett D, Edelhoff D, Frankenberger R, et  al. Severe tooth wear: European Consensus Statement on management guidelines. J Adhes Dent. 2017;19(2):111–9. 5. Shellis RP, Addy M. The interactions between attrition, abrasion and erosion in tooth wear. Monogr Oral Sci. 2014;25:32–45. 6. Wetselaar P, Wetselaar-Glas MJM, Katzer LD, Ahlers MO. Diagnosing tooth wear, a new taxonomy based on the revised version of the Tooth Wear Evaluation System (TWES 2.0). J Oral Rehabil. 2020;47(6):703–12. 7. Hemmings K, Truman A, Shah S, Chauhan R. Tooth wear guidelines for the BSRD Part 1: Aetiology, diagnosis and prevention. Dent Update. 2018;45:3–10. 8. Smith BG, Knight JK. An index for measuring the wear of teeth. Br Dent J. 1984;156(12):435–8. 9. Bartlett D, Ganss C, Lussi A. Basic Erosive Wear Examination (BEWE): a new scoring system for scientific and clinical needs. Clin Oral Invest. 2008;12(Suppl. 1):S65–S8. 10. Salas MM, Nascimento GG, Huysmans MC, Demarco FF.  Estimated prevalence of erosive tooth wear in permanent teeth of children and adolescents: an epidemiological systematic review and meta-regression analysis. J Dent. 2015;43(1):42–50. 11. NHS Digital. Adult Dental Health Survey 2009—Summary report and thematic series [NS]. London: The Health and Social Care Information Centre; 2011. [Available from: https:// digital.nhs.uk/data-and-information/publications/statistical/adult-dental-health-survey/]. 12. NHS Digital. Child Dental Health Survey 2013, England, Wales and Northern Ireland. London: NHS Digital; 2015. [Available from: https://digital.nhs.uk/data-­and-­information/publications/ statistical/children-­s-­dental-­health-­survey/]. 13. Harding MA, Whelton HP, Shirodaria SC, O'Mullane DM, Cronin MS. Is tooth wear in the primary dentition predictive of tooth wear in the permanent dentition? Report from a longitudinal study. Community Dent Health. 2010;27(1):41–5. 14. Kamal Y, O’Toole S, Bernabé E. Obesity and tooth wear among American adults: the role of sugar-sweetened acidic drinks. Clin Oral Investig. 2020;24(4):1379–85. 15. Saads Carvalho T, Lussi A. Chapter 9: Acidic beverages and foods associated with dental erosion and erosive tooth wear. Monogr Oral Sci. 2020;28:91–8. 16. Valenzuela MJ, Waterhouse B, Aggarwal VR, Bloor K, Doran T. Effect of sugar-sweetened beverages on oral health: a systematic review and meta-analysis. Eur J Public Health. 2020; 17. Wazani BE, Dodd MN, Milosevic A. The signs and symptoms of tooth wear in a referred group of patients. Br Dent J. 2012;213(6):E10.

2  Tooth Wear and Population Oral Health

25

18. Lussi A, Megert B, Shellis RP, Wang X.  Analysis of the erosive effect of different dietary substances and medications. Br J Nutr. 2012;107(2):252–62. 19. Lussi A. Dental erosion: from diagnosis to therapy. In: Publishers K, editor. Monographs in oral science. Basel; 2006. 20. Ganss C, Schlechtriemen M, Klimek J. Dental erosions in subjects living on a raw food diet. Caries Res. 1999;33(1):74–80. 21. Sovik JB, Skudutyte-Rysstad R, Tveit AB, Sandvik L, Mulic A. Sour sweets and acidic beverage consumption are risk indicators for dental erosion. Caries Res. 2015;49(3):243–50. 22. NICE. Dental recall guidelines. London: National Institute for Health and Clinical Excellence; 2004. Report No.: CG019 23. NICE. Surveillance Report 2018 Dental checks: intervals between oral health reviews (2004) NICE guideline CG19. London: National Institute for Health and Clinical Excellence; 2018. [Available from: https://test.nice.org.uk/guidance/cg19/resources/ surveillance-report-2018-dental-checks-intervals-between-oral-health-reviews2004-nice-guideline-cg19-4898003869/chapter/overview-of-2018-surveillance-methods]. 24. UK Chief Medical Officers’. Alcohol consumption: advice on low risk drinking: UK chief medical officers’ guidelines on how to keep health risks from drinking alcohol to a low level. London: UK Government; 2016. [Available from: https://www.gov.uk/government/ publications/alcohol-consumption-advice-on-low-risk-drinking]. 25. UK Chief Medical Officers’. Physical activity guidelines: UK Chief Medical Officers’ Report. London: UK Government; 2019. [Available from: https://www.gov.uk/government/ publications/physical-activity-guidelines-uk-chief-medical-officers-report]. 26. Moazzez R, Austin R. Medical conditions and erosive tooth wear. Br Dent J. 2018;224(5): 326–32.

3

Risk Factors in Tooth Wear Lucy Slater, Andrew Eder, and Nairn H. F. Wilson

3.1

Introduction

Should we be more proactive in screening and intervening in patients who present with early signs of tooth wear? Without preventive and early management, caries and periodontal disease are destructive processes that can cause pain, tooth loss, varying degrees of dental disability and deteriorations in dental attractiveness. Tooth wear is another damaging process that can have profound effects on appearance and self-esteem with the possibility of reduced function, with or without alterations in jaw movements, posture and path of closure. While caries, periodontal disease and tooth wear are all largely preventable, national guidelines on a preventive approach to oral healthcare provision, such as The Delivering Better Oral Health Toolkit, have previously focused on limited to advice on the prevention of caries and periodontal disease. Only recently has there been a large enough body of evidence to develop guidelines on the prevention of tooth wear [1]. As with caries, it is important to distinguish between ‘active’ and ‘arrested’ wear both in assessment and care planning. Failure to prevent and manage active tooth wear is contrary to the patient-­centred, preventatively orientated, minimum intervention philosophies and concepts driving current trends in clinical practice. This is generating a huge health and financial burden on patients which can only increase if the care of patients with increasing levels of asymptomatic tooth wear is to be funded in the future. Whatever future

L. Slater (*) Dental Officer, CNWL Dental Services, Buckinghamshire, UK A. Eder UCL Eastman Dental Institute and Harley Street Dental and Implant Clinic, London, UK e-mail: [email protected] N. H. F. Wilson College of General Dentistry, London, UK © Springer Nature Switzerland AG 2022 A. Eder, M. Faigenblum (eds.), Tooth Wear, BDJ Clinician’s Guides, https://doi.org/10.1007/978-3-030-86110-0_3

27

28

L. Slater et al.

funding arrangements may exist, identifying tooth wear markers and risk assessing patients for pathological tooth wear should form part of regular oral health assessments. The aim of this chapter is to highlight the growing importance of early identification of patients who may be at risk of pathological tooth wear, provide an overview of known tooth wear markers, and suggest the development of a system to assess susceptibility to tooth wear.

3.2

Increasing Importance of Tooth Wear

The population is changing; it is growing older, and people are retaining more teeth for longer. It is, therefore, becoming increasingly likely that dental practitioners will see more cases of moderate and severe tooth wear. The population pyramid (Fig. 3.1) illustrates the UK’s increasingly ageing population. The National Population Projections: 2018-based Statistical Bulletin stated that there will be an increasing number of older people; the proportion aged 85 years and over is projected to almost double over the next 25 years [2]. The 2009 Adult Dental Health Survey highlighted that 22% fewer people were edentulous in 2009 than in 1978. The survey also revealed that the prevalence of decay and periodontal pockets ≥4 mm has fallen from 46% to 28% and from 55% to 45% respectively since 1998 [3]. Meanwhile, tooth wear has increased by 10%, with more significant increases in the younger age groups from 16 to 44 years of age [4]. Being ‘short in the tooth’ (rather than ‘long’) is unlikely to become the next term to colloquially refer to older people. However, it is important to identify those who may be at risk of tooth wear now, especially young patients who expect to keep their teeth for many decades and until they reach 100 years of age or even older. To do this, potential tooth wear markers need to be identified and their potential role investigated thoroughly.

3.3

Tooth Wear Markers

The remainder of this chapter will consider physical, medical and social markers as predictors and identifiers of risk to develop pathological, multifactoral tooth wear— wear in excess of the physiological wear expected for the patient’s age which may cause aesthetic and functional problems [5]. To analyse risk and appropriately prevent unnecessary tooth wear, patients with markers need to be identified. The Cariogram is a tool used to graphically represent and predict caries risk, taking into account past caries experience and biological factors, including related diseases, diet, amount of plaque, bacteria (specifically, mutans Streptococci), fluoride exposure, qualities of saliva and clinical judgement [6]. This tool is freely available on the internet and can be used to inform clinicians and educate patients [6]. Similarly, in the management of periodontitis, prediction of disease progression and tooth loss is topical, with a systematic review having been published in 2015 [7].

3  Risk Factors in Tooth Wear Fig. 3.1  Age Structure of UK Population mid-2018 and mid-2043, highlighting the growing number of people in the UK. Source National Population projections—Office for National Statistics. Updated to reflect latest data since original publication  Age Structure of UK Population mid-2018 and mid-2043 contains public sector information licensed under the Open Government Licence v3.0 as per: http://www. nationalarchives.gov.uk/ doc/open-­government-­ licence/version/3/

29

2018 2043 105 - 109

Females

Males

100 95 90 85 80 75 70 65 60 55 50 45 40 35 30 25 20 15 10 5 0

500

250

0

0

250

500

Population (Thousands)

This review endorsed the use of prediction tools, suggesting that further research is necessary in the field [7]. A similar tool, perhaps the ‘Wearogram’, would help identify those at risk of pathological tooth wear, and thereby help to predict and prevent unnecessary loss of sound tooth tissue. The factors set out in Tables 3.1–3.3 would need to be considered in developing the proposed tool. Such a predictor would complement well existing indices such as the Basic Erosive Wear Examination [8].

30

L. Slater et al.

Tables 3.1-3.3 detail the markers of tooth wear organised into physical, medical and social factors. Application of these markers could help differentiate between early pathological and physiological wear. For example, a 22-year-old (Fig. 3.2) has developed group function as a consequence of wear of all four canines, resulting in Table 3.1  Physical markers of tooth wear Extraoral Intraoral—soft tissues Intraoral—hard tissues

Hypertrophic masseters [10] (Fig. 3.3) Buccal keratoses [5] (Fig. 3.4) Cheek biting—made worse by xerostomia [10] (Fig. 3.5) Scalloping of the tongue [14] (Fig. 3.6) Loss of canine guidance (Fig. 3.7) Shortened dental arch for over 15 years caused significantly more wear of the premolars [15] Wear facets

Table 3.2  Medical markers of tooth wear Genetics

Pain

Psychology

Saliva

Sleep disorders Stomach acid regurgitation

A recent study has shown that genetic variation within enamel formation genes, such as amelogenin, is associated with erosive wear and its severity [16]. This shows that dental wear and erosion susceptibility could have an intrinsic component rather than being simply environmental; this supports the need for greater research into tooth wear biomarkers An exploratory study of sleep bruxism showed that facial pain in the morning is more common amongst bruxists with attrition. However, this study did not show any significance between saliva flow rate, buffering capacity, tender muscles of mastication or maximum opening, and the attrition status of the patients [17]. Therefore, it might be possible to use facial pain as a severity indicator of bruxism and therefore a tooth wear marker Those with ADHD, inattention and/or hyperactivity-impulsivity, are more likely to have bruxism [18] Anxiety and mood are often seen in those that brux [10]. A study published in 2015 showed that bruxism, clenching and anxiety are negatively correlated to levels of the inhibitory neurotransmitter, gamma aminobutyric acid (GABA) as well as glutamate [19]. This illustrates a need for close multidisciplinary teamwork between the patient’s GP and dentist if bruxism is thought to be the cause of the tooth wear Saliva is vital to protecting the teeth, buffering acid, remineralisation of enamel and pellicle formation [10, 20]. If the patient is a sleep bruxist as well, this augments the tooth wear [10] Conditions reducing saliva, including:  •  Congenital rubella syndrome  •  Prader-Willi syndrome  •  Sjogren’s syndromes [20] Drug-induced xerostomia Sports-related dehydration is also a risk factor for tooth wear [20], and so playing a sport should be considered a risk marker Sleep apnoea and snoring aggravate bruxism [10] Acidic reflux causes dental erosion as mentioned previously [10] Anorexia bulimia involves the action of purging and recurrently exposes the patient’s mouth to an acidic environment, contributing to wear [11]

3  Risk Factors in Tooth Wear

31

Table 3.3  Social markers of tooth wear Alcohol misuse Caffeine Erosive diet Recreational drug users

Smoking Sports

A study of the dental health of 107 alcohol misusers (where 80% consumed 100 units of alcohol per week) was conducted in South East London. It also showed that this cohort have a greater amount of tooth wear and highlighted this as an important marker [13] Aggravates bruxism [10] All tooth wear can be accelerated with erosive foods and drinks. These substances are also risk markers Recreational drug users are more likely to have dental problems, including tooth wear [12]. The Class A drug Ecstasy is especially relevant, as the Home Office have reported an increase of 95,000 (from 3.9% to 5.4%) in 16 to 24-year-olds between 2013/14 and 2014/15 using Ecstasy [21]. Those using Ecstasy have less saliva and clench excessively, causing more occlusal than incisal attrition [12] Aggravates bruxism [10] Sport-induced dry mouth as mentioned previously [20] Despite finding it difficult to find evidence of an association between weightlifters and clenching or tooth wear, they are a highly susceptible cohort; anecdotally and online, there are reports of clenching whilst lifting weights. This possible correlation could be exaggerated by the use of amino acids and protein shakes, before and after exercising. This could be priming the teeth for increased wear Swimmers and other athletes are likely to rely heavily on sports drinks and therefore are at an increased risk of erosive wear

Fig. 3.2  22-year-old found to have group function in right and left lateral excursions, following wear of the canines Fig. 3.3 25-year-old female with hypertrophic masseters

32

L. Slater et al.

Fig. 3.4 22-year-old female with bilateral occlusal frictional keratosis

Fig. 3.5 25-year-old female with parafunctional cheek biting

Fig. 3.6 25-year-old female with tongue scalloping

the loss of canine guidance. Although only relatively mild, could this wear be a marker of future severe pathological wear? Bruxism is a known cause of tooth wear [9] and, therefore, factors predisposing to bruxism are also included in Tables 3.1, 3.2 and 3.3. Most notably, bruxism is common among those with psychological stress [10], eating disorders [11], and the misuse of drugs [12] and alcohol [13].

3  Risk Factors in Tooth Wear

33

Fig. 3.7  30-year-old male with multifactorial moderate tooth wear

Fig. 3.8  45-year-old male with multifactorial severe tooth wear caused by dietary erosion and bruxism

Medical and social markers rely heavily on the medical history and it may be difficult for dental professionals to obtain such personal details in this way, particularly on first consultation. It is therefore imperative that healthcare teams work together closely. If severe tooth wear is observed, careful conversation should attempt to elicit a thorough history to identify its aetiology and identify whether the individual should be referred for further advice and assistance.

3.4

Progression of Wear

The 22-year-old female in Figs. 3.2 and 3.4 has signs of multifactorial tooth wear. She has mild chipping of her anterior central incisors, loss of canine guidance, buccal frictional keratosis, tender masseters and a high-risk erosive diet. The 30-year-­ old male in Fig. 3.7 has moderate multifactorial tooth wear, with similar signs and symptoms to the female in Fig. 3.4. When is the right time to intervene? Would these patients have benefitted from composite canine risers to restore canine guidance as soon as it was lost? In the absence of any preventive intervention, will the wear remain active and will these patients require full mouth

34

L. Slater et al.

restorative rehabilitation at some time in the future? When do the benefits of intervention exceed possible negative effects? What markers did the 45-year-old in Fig. 3.8 and the 30-year-old patient in Fig. 3.7 have at 20 years of age? The 45-yearold patient (Fig. 3.8) now seeks treatment to restore his appearance and function. Such treatment, including long-term maintenance, brings with it a large health and financial burden, irrespective of the system under which it is being provided. Notwithstanding benefits to the increasing numbers of tooth wear patients, if early intervention could be shown to prevent severe tooth wear and subsequent loss of function and aesthetics, it would fully justify the research cost of better understanding the importance and application of tooth wear markers.

3.5

Conclusion

The majority (76%) of the UK population have tooth wear [4]. Tooth wear is therefore widely prevalent and rising alongside increased life expectancy and the improved management of caries and periodontal disease. As a result, the time commitment and financial burden of managing tooth wear will be significant for both the dental team and patient alike. In view of this projected increase in need for care, an effective and efficient risk assessment tool (for example, the proposed ‘Wearogram’) to support the identification of tooth wear markers is recommended and will be invaluable to encourage prevention through education and early, non-­ invasive, intervention. Identifying markers of pathological tooth wear as early as possible and instigating a proactive approach to prevention will assist in at least containing future needs to manage severe tooth wear. Acknowledgements  This chapter is adapted from the following article which was originally published by the Faculty of General Dental Practice UK in the Primary Dental Journal. Slater L, Eder A, Wilson N. Worn’ing: Tooth Wear Ahead. Prim Dent J. 2016 Aug 1;5 (3):38-42. https://doi.org/10.1177/205016841600500304. Copyright © 2016 Faculty of General Dental Practice UK (FGDP[UK]).

References 1. Office for Health Improvement and Disparities, Department of Health and Social Care, NHS England, NHS Improvement. Delivering better oral health: An evidence-based toolkit for prevention, Version 4. London: OHID, DHSC, 2021. [Available from: https://www.gov.uk/government/ publications/delivering-better-oral-health-an-evidence-based-toolkit-for-prevention. 2. National population projections: 2018-based statistical bulletin. Office for National Statistics. Available at: https://www.ons.gov.uk/peoplepopulationandcommunity/populationandmigration/populationprojections/bulletins/nationalpopulationprojection s/2018based 3. Fuller E, Steele J, Watt R, Nuttal N, O’Sullivan I, Lader D, O’Sullivan I, Lader D, editors. Adult Dental Health Survey 2009: Theme 1: Oral health and function. London: The Health and Social Care Information Centre; 2011.

3  Risk Factors in Tooth Wear

35

4. White D, Pitts N, Steele J, Sadler K, Chadwick B, O’Sullivan I, editors. Adult Dental Health Survey 2009: Theme 2 disease and related disorders. London: The Health and Social Care Information Centre. p. 2011. 5. Mehta SB, Banerji S, Millar BJ, Suarez-Feito J-M. Current concepts on the management of tooth wear: Part 1: Assessment, treatment planning and strategies for the prevention and the passive management of tooth wear. Br Dent J. 2012;212(1):17–27. 6. Brathall D, Petersson GH. Cariogram—a multifactorial risk assessment model for a multifactorial disease. Commun Dent Oral Epidemiol. 2005;33(4):256–64. 7. Lang NP, Suvan JE, Tonetti MS. Risk factor assessment tools for the prevention of periodontitis progression: a systematic review. J Clin Periodontol. 2015;42(SI):S59–70. 8. Bartlett D, Ganss C, Lussi A. Basic erosive wear examination: a new scoring system for scientific and clinical needs. Clin Oral Investig. 2008 March;12(Supp 1):65–8. 9. Bader G, Lavigne G. Sleep bruxism: an overview of an oromandibular sleep movement disorder. Sleep Med Rev. 2000;4(1):27–43. (Review Article) 10. Lavigne GJ, Khoury S, Abe S, Yamaguchi T, Raphael K. Review article: Bruxism physiology and pathology: an overview for clinicians. J Oral Rehabil. 2008;35(7):476–94. 11. Cowan C. Identification and diagnosis of tooth wear in adults for the general dental practitioner. Prim Dent J. 2016;5(3) ePub 12. Shekarchizadeh H, Khami MR, Mohebbi SZ, Ekhtiari H, Virtanen JL.  Oral health of drug abusers: a review of health effects and care. Iran J Public Health. 2013;42(9):929–40. 13. Harris CK, Warnakulasuriya KA, Johnson NW, Gelbier S, Peters TJ. Oral health in alcohol misusers. Commun Dent Health. 1996;13(4):199–203. 14. Lobbezoo F, Ahlberg J, Manfredini D, Winocur E. Are bruxism and bite causally related? J Oral Rehabil. 2012;39(7):489–501. 15. Witter DJ, Greugers NHJ, Kreulen CM, de Haan AFJ. Occlusal stability in shortened dental arches. J Dent Res. 2001;80(2):422–36. 16. Sovik JB, Vieira AR, Tveit AB, Mulic A. Enamel formation genes associated with dental erosive wear. Caries Res. 2015;49(3):236–42. 17. Jonsgar C, Hordvik PA, Berge ME, Johansson AK, Svensson PO, Johansson A. Sleep bruxism in individuals with and without attrition-type tooth wear: An exploratory matched case-control electromyographic study. J Dentist. 2015;43(12):1504–10. 18. Chiang HL, Gau SSF, Ni HC, Chiu YN, Shang CY, Wu YY, et al. Association between symptoms and subtypes of attention-deficit hyperactivity disorder and sleep problems/disorders. J Sleep Res. 2010;19(4):535–45. 19. Dharmadhikari S, Romito LM, Dzemidzic M, Dydak U, Xu J, Bodkin CL, et al. GABA and glutamate levels in occlusal splint-wearing males with possible bruxism. Arch of Oral Biol. 2015;60(7):1021–9. 20. Young W, Khan F, Brandt R, Savage N, Razek AA, Huang Q. Syndromes with salivary dysfunction predispose to tooth wear: case reports of congenital dysfunction of major salivary glands, Prader-Willi, congenital rubella, and Sjögren’s syndromes. Oral Surg Oral Med Oral Path Oral Radiol Endod. 2001;92(1):38–48. 21. Lader D, editor. Drug misuse: findings from the 2014/15 Crime Survey for England and Wales. 2nd ed. London: Home Office; 2015.

4

Saliva and Tooth Wear Raelene Sambrook

4.1

Introduction

Saliva is described in the Oxford Dictionary as a ‘watery liquid secreted into the mouth by glands, providing lubrication for chewing and swallowing, and aiding digestion’. This simple definition fails to illustrate the complexity or heterogeneity of this biological fluid nor its pivotal role in maintaining oral health. In the context of erosive tooth wear, the capacity of saliva to protect the dental hard tissues is compromised by either the quality or quantity of the saliva or the frequency and duration of acid attacks.

4.2

Saliva Secretion

In the absence of exogenous stimuli, resting or unstimulated saliva is predominantly excreted from the submandibular glands (60%), the parotid glands (25%), the sublingual glands (7%) and hundreds of minor salivary glands (8%) [1, 2]. The minor salivary glands are located throughout the oral cavity including the labial, buccal, palatal, lingual and retromolar regions [3]. Resting or unstimulated saliva flow rate is estimated at 0.3 mL/min [4], with salivary flow during sleep falling to nearly zero [2, 4]. Stimulated flow rate increases to 1.5–2.0 mL/min, though flow rates up to 7 mL/min have been reported [2, 5]. Salivary secretion is controlled by the autonomic nervous system with both the parasympathetic and sympathetic nervous systems regulating salivary production via reflex pathways. For example, an increase in salivary production is associated with stimulation of gustatory, masticatory and olfactory receptors. Apart from the ingestion of food and drink, stimulation of saliva production is also regulated by R. Sambrook (*) Prosthodontics Department, UCL Eastman Dental Institute, London, UK e-mail: [email protected] © Springer Nature Switzerland AG 2022 A. Eder, M. Faigenblum (eds.), Tooth Wear, BDJ Clinician’s Guides, https://doi.org/10.1007/978-3-030-86110-0_4

37

38

R. Sambrook

stretch receptors in the stomach due to nausea and/or vomiting [3]. Saliva production can also be affected by circadian and circannual rhythms. In addition, emotional states (depression, anxiety, stress) which influence higher brain centres and the central nervous system can affect secretion [1, 2]. Other factors which influence salivary secretion include ambient temperature and hydration, yet, age-related changes are equivocal [1, 6–8]. Lastly, medical conditions/diseases, medications and medical treatment can affect salivary secretion, disturbing both flow and composition [1, 2, 7, 9, 10]. Whilst it has been estimated that the total volume of secreted saliva, is approximately 600 mL per day [11], individual variations will influence this ‘normal’ volume [2].

4.3

Composition and Physical Properties of Saliva

Saliva is composed predominantly of water (99%). The other 1% includes salts and proteins which are soluble in the aqueous phase [12]. The proteins are either of salivary gland origin or exfoliated epithelial cells and microorganisms from the oral cavity [1]. The major salivary proteins are mucins (20–30%), immunoglobulins (5–15%) and glycoproteins in smaller quantities, with their presence increasing upon stimulation. The major salivary proteins account for approximately 50% of total salivary protein [13]. The minor salivary proteins consist of antimicrobial proteins with enzymic and nonenzymic activity. The electrolytes found in saliva include sodium (Na+), potassium (K+), calcium (Ca2+), magnesium (Mg2+), chlorides (Cl−), phosphates (HPO32−) and bicarbonates (HCO3−) [12]. In addition, nitrogenous products such as urea and ammonia (NH3) are present. The composition and physical properties of saliva are affected by the flow rate and the gland from which the saliva is excreted [1]. Each of the different glands produce different quantities of either serous (watery, protein-rich) or mucous (mucin rich) fluid, depending on its cellular makeup (Table 4.1). Unstimulated saliva has a higher concentration of mucins and consequently presents as a more mucous-rich, viscous fluid for the purpose of moistening and lubricating the oral cavity and oesophageal mucosa. In comparison, stimulated saliva, which flows at an increased rate, is more serous (watery consistency) and aids in mastication and clearance of food from the oral cavity [4]. Though interestingly, stimulated saliva varies in the proportion of secretions between the different salivary glands [14]. For example, upon mechanical stimulation (i.e. chewing) the parotid glands dominate salivary production, accounting for 50% of the volume of saliva produced. Chemical stimulation, either from the tastant (sour, bitter, umami and sweet) or the olfactant, will result in differences in the activation of the parotid and submandibular glands.

4  Saliva and Tooth Wear

39

Table 4.1  Salivary glands, cell type, secretory product and contribution to saliva, both at rest and when stimulated (adapted from Pedersen et al. 2018 [1]) Contribution (%) to whole saliva volume Secretory Resting Stimulated Acinar cell type product Major salivary Serous, mixed, 92% 92% glands mucous   Parotid glands Serous Watery, 25% 50% amylase-rich   Submandibular Mixed, mainly Viscous, 60% 35% glands mucous mucin-rich   Sublingual glands Mixed, mainly Viscous, 7–8% 7–8% mucous mucin-rich Minor salivary Serous, mixed, 8% 8% glands mucous

The normal pH of saliva is 6 to 7 though, depending on flow, it can range from 5.3 (low) to 7.8 (high) [2].

4.4

The Role of Saliva in Oral Health

Saliva is a unique biologic fluid containing organic and inorganic products whose independent and interactive functions are not yet fully realised. Nevertheless, saliva’s role in maintaining oral health has been recognised as lubrication of the oral surfaces, antibacterial, anti-viral and anti-fungal actions, facilitating oral clearance, maintaining tooth mineralisation, having buffering capacity to counteract acid attacks, and establishing an acquired pellicle on the tooth surface [4, 15]. Figure 4.1 illustrates how the composition of saliva contributes to its protective mechanisms. Mucin-rich unstimulated saliva lubricates and protects the oral tissues. These mucins, along with the other proteins (glycoproteins, immunoglobulins and antimicrobials) also provide numerous antibacterial, anti-viral and anti-fungal functions [1, 2, 4]. Maintaining a healthy oral environment is also affected by the salivary flow. The continual production of saliva necessitates the process of swallowing which facilitates the oral clearance of noxious oral microbiota. In addition to the elimination of oral microorganisms, oral clearance assists with removal of dietary sugars and maintenance of the pH in a neutral range though dilution of acids. In the unstimulated state, the concentrations of calcium (Ca2+) and phosphate (HPO32−) ions in saliva sustain equilibrium with the tooth, maintaining tooth mineralisation. Effectively, saliva saturated in calcium and phosphate ions prevents the dissolution of hydroxyapatite, the mineral matrix of the tooth. The pH at which

40

R. Sambrook

Proline-rich proteins Statherin Ca. phosphate

Prol-rich glycoprotein Mucins

Bicarbonate Phosphate Proteins

Mucins

Remineralization

Functions of saliva

Buffering

FOOD

Digestion Taste

Bolus Zinc

Antibacterial

TEETH

Lubrication, viscoelasticity

Amylase DNAse, RNAse Lipase Protease

Inhibition of demineralization

Mucins

MICROBES

Mucins Lysozym Lactoferrin Lactoperoxidase Histamin Agglutinin Cystatins VEGh

Antifungal

Antiviral

Immunoglobulins Mucins Histatins

Mucins Immunoglobulins Cystatins

Fig. 4.1  Main functions of saliva in relation to its constituents (from van Nieuw Amerongen et al. 2004 [13])* *Reproduced with permission from S. Karger AG, Basel

saliva is saturated with respect to a particular mineral is the ‘critical pH’ [16]. In the event of an acid attack, the pH of saliva is at risk of dropping below the critical pH resulting in a reduction of the mineral saturation. Consequently, undersaturation of calcium (Ca2+) and phosphate (HPO32−) ions in saliva will result in tooth dissolution through mineral loss. Whilst both salivary flow and oral clearance assist with maintaining the pH above the critical pH, the buffering capacity of saliva also has an influence. For unstimulated saliva, two buffering systems are at work, the bicarbonate and the phosphate buffering systems. In contrast, for stimulated saliva, the bicarbonate buffering system is responsible for 90% of the total buffer capacity. Of these two buffering systems, the most effective buffering is achieved by the interaction of bicarbonate (HCO3−) with acid. Predominant phosphate ions (HPO32−) and nitrogenous products, such as urea, in unstimulated saliva provide only minor buffering capability [17]. It has been proposed that the critical pH values for demineralisation of enamel, in an erosive challenge, range from 3.9 to 6.5 [18]. Yet, for dentine, the critical pH is not defined as the organic collagen matrix has also been demonstrated to have

4  Saliva and Tooth Wear

41

buffering properties [19]. To date, less research has focused on dentine and consequently, the process of demineralisation is less well understood. The negative effects of a low pH on tooth integrity and the capacity of the tooth to remineralise has also been demonstrated to be affected by the acquired salivary pellicle. This acquired pellicle is an organic, proteinaceous, bacteria-free film which forms on dental surfaces instantly [20]. It can be removed mechanically or through a strong and prolonged acid attack. Whilst the composition of the acquired pellicle coating dentine and enamel is similar in composition, studies have indicated that it functions differently. For enamel, the acquired pellicle has a selective permeability function, regulating demineralisation and remineralisation by creating a diffusion barrier [21]. In contrast the acquired pellicle on dentine acts as an ion permeable network limiting its protective properties against acid attack [21, 22]. Nevertheless, the acquired pellicle is regarded as one of the key factors in the physiological prevention of dental erosion [20, 22] and inter-individual differences in composition, thickness and maturation time may influence its protective capacity [15].

4.5

Saliva and Erosive Tooth Wear

Erosive tooth wear is defined as a chemical-mechanical process resulting in a cumulative loss of hard dental tissue not caused by bacteria [23]. Whilst acid is considered the main cause, progression is also accelerated by mechanical factors such as attrition and/or abrasion. The process of erosive tooth wear (Chap. 6) is the consequence of initial loss of mineral from the enamel surface resulting in a loss of hardness (softening) which makes the enamel surface vulnerable to physical impacts [19]. Progressive loss of enamel results in dentine becoming increasingly exposed [19]. Dentine, given its different composition, behaves differently to enamel in an erosive challenge. This process is less well understood [7, 19]. Under acid attack, the mineral component of dentine is dissolved whilst the organic component is retained. It is believed that this demineralised collagen is somewhat more resistant to mechanical impacts compared to demineralised enamel [19]. Saliva has been recognised as one of the main biological parameters which modifies the erosive process [24]. For each individual, there is a threshold at which point salivary flow and function cannot counteract an erosive challenge [15]. Consequently, susceptibility to erosion is affected by the capacity of saliva to clear erosive food and beverages, maintain an effective pellicle, buffer the change in intra-oral pH and support remineralisation [15]. Of the protective mechanisms of saliva, the role of the acquired pellicle is being recognised as increasingly important. For example, a recent study has illustrated a difference in the capacity of the acquired pellicle from

42

R. Sambrook

‘healthy’ subjects compared with subjects who have erosive tooth wear, to counteract the effects of an erosive challenge [20]. It is unclear how pellicle composition and thickness influence its protective mechanism against erosion [21]. Nevertheless, whilst frequency and duration of acid exposure (either intrinsic or extrinsic) are recognised as a risk factor for erosion, so are the inter-individual differences of saliva [23]. In addition to the effectiveness of saliva in counteracting the effects of acid exposure, the susceptibility of the tooth surface is affected by its position in the dental arch [16]. This site-specific susceptibility to erosion has been attributed to the position of the tooth relative to type of salivary gland, the composition of saliva produced and the acquired pellicle thickness [24, 25]. Salivary dysfunction caused by a decrease in salivary flow rate can have significant impacts on the oral health of an individual. Interestingly, tooth erosion is not always recognised as a disease outcome of hyposalivation and oral dryness [10, 26]. Whilst patients with severe hyposalivation, due to disease or radiotherapy, experience accelerated demineralisation and reduced remineralisation of enamel and dentine, this is typically associated with an increase in smooth surface and root caries. In comparison, whilst susceptibility to dental erosion is expected, it is not a predominant outcome [26–30]. Recently, in a review by Wetselaar et al. (2019), direct and indirect associations between oral dryness and tooth wear were assessed. The authors concluded that evidence supported a direct association between oral dryness and both mechanical and chemical tooth wear [31]. Nevertheless, further research, including the use of animal models, is focused at understanding the complex interplay of the factors in the oral environment (saliva, enamel phenotype, diet) and the process of erosion [32].

4.6

Saliva Tests (Sialometry)

Management of erosive tooth wear requires the aetiology to be determined [23]. This may be attributable to patient related factors, nutritional factors or occupational factors. Of the patient related factors, this may be due to salivary hypofunction, poor buffering capacity or exposure to endogenous acid. To assess salivary flow, it has been proposed that saliva testing, a non-invasive procedure, provides an objective measure on the quantity of saliva [33]. The use of saliva tests which measure stimulated and unstimulated flow rate as well as of the buffer capacity of saliva have also been proposed as a tool to provide useful information about the individual risk of a patient [15]. Nevertheless, limited research supports the use of routine saliva testing for risk assessment of tooth wear [34]. In addition, the evidence to support the efficacy of saliva testing to quantify flow rates has been questioned by some authors [35]. Studies which have assessed saliva testing against visible tooth wear have also shown equivocal results relating salivary quantity or quality with clinical signs of erosive tooth wear [34, 36, 37].

4  Saliva and Tooth Wear

4.7

43

Xerostomia

Hyposalivation is defined when the unstimulated whole salivary flow rate is ≤0.1 mL/min and/or the stimulated whole salivary flow rate is ≤0.5–0.7 mL/min [5]. In comparison, xerostomia is the subjective sensation of a dry mouth and surprisingly, it may or may not correlate with a reduced salivary flow rate [5]. Ongoing research efforts are directed at developing and refining a xerostomia questionnaire to provide a valid and reliable measurement tool [30]. The scope of questions include ‘my mouth feels dry’, ‘my mouth feels dry when eating a meal’ and ‘my lips feel dry’. Whilst patients who suffer from xerostomia have been shown to have a greater incidence of dental caries [38], there is also some evidence to suggest that xerostomia is associated with increased tooth wear [39]. Saliva and COVID-19

On the 11th March 2020, the WHO Director-General declared COVID-19 a pandemic [40]. At the time of writing (January 2021), there were over 82 million individuals who have been diagnosed with the disease and more than 1.8 million people have lost their life [41]. Much has been learnt about the transmission of the virus (SARS-CoV-2), clinical features of those infected and medical interventions to save lives. What is also emerging in the literature are questions and correlations between hyposalivation, xerostomia and taste disturbances as they relate to the disease, either as a predisposing factor or as a repercussion of the disease. The oral cavity is considered a main route of infection for COVID-19 [42]. It has been hypothesized that individuals who suffer from hyposalivation may be at greater risk of severe acute respiratory syndrome coronavirus 2 (SARS-­ CoV-­2) due to a reduction in the first-line defence that saliva provides [43]. This is through both the proteins and peptides of saliva (e.g. mucins and cystatins) which have anti-viral properties, and the lubrication and cleansing properties that adequate salivary flow provides to the soft tissue and mucosa [2, 43, 44]. It is acknowledged that COVID-19 is more severe in patients over 50 years of age who have comorbidities and the use of medication which may impact on salivary flow [42, 45]. Whether hyposalivation itself is a risk factor is yet to be determined, though this could have implications on objective clinical assessment for salivary flow as a risk factor for acute respiratory infections in the future. Observations of oral manifestations of COVID-19 have also been published, either prodromal or concomitant. In relation to saliva, it has been proposed that xerostomia is a clinical manifestation of COVID-19 [46]. This problem of dry mouth has been associated with swallowing difficulties and the need to frequently sip liquid to assist with consuming dry food [47]. Similarly many of the patients who have reported xerostomia also report altered taste (dysgeusia) [47, 48].

44

R. Sambrook

It has been suggested that SARS-CoV-2 may induce acute infection of the salivary glands (sialadenitis) [44]. The symptoms for the individual include pain and salivary dysfunction. Though, there is also the risk of inflammatory damage which may induce chronic sialadenitis affecting salivary quantity and quality for a longer duration of time [49]. Lastly neurological complications of COVID-19 have been assessed. With COVID-19 sufferers having an increased risk of neurological disorders including anxiety and depressed mood [50], there is also the risk for depressed salivary flow. This will be of particular importance for those patients’ suffering from long COVID. Whilst there is still much to learn, dentists should be aware of how COVID-19 may be linked to longer term salivary hypofunction or xerostomia and the related oral health issues these conditions cause.

4.8

Conclusion

Erosive tooth wear is a potentially destructive disease associated with the dental hard tissues. Saliva is recognised as the main defence for preventing dissolution of the hard tissue. Whilst the importance of saliva is recognised, it is unclear if the quantity, quality or the buffering capacity of saliva is impaired in patients who experience erosive tooth wear. More recent research in patient susceptibility to erosive tooth wear has focused on the composition and thickness of the salivary pellicle. Nevertheless, it should be recognised that for many patients, it is both the frequency and duration of acid exposure which supersedes the effectiveness of saliva, resulting in hard tissue loss.

References 1. Pedersen AML, Sørensen CE, Proctor GB, Carpenter GH, Ekström J.  Salivary secretion in health and disease. J Oral Rehabil. 2018;45:730–46. https://doi.org/10.1111/joor.12664. 2. Humphrey SP, Williamson RT. A review of saliva: normal composition, flow and function. J Prosthet Dent. 2001;85:162–9. 3. Berkowitz B, et al. Chapter 16: Salivary glands. In: Oral anatomy, histology and embryology. 5th ed. Mosby/Elsevier; 2018. p. 303–22. 4. Dawes C, et al. The functions of human saliva: a review sponsored by the World Workshop on Oral Medicine VI.  Arch Oral Biol. 2015;60:863–74. https://doi.org/10.1016/j. archoralbio.2015.03.004. 5. Villa A, et  al. World workshop on oral medicine VI: a systematic review of medication-­ induced salivary gland dysfunction: prevalence, diagnosis and treatment. Clin Oral Invest. 2015;19:1563–80. https://doi.org/10.1007/s00784-­015-­1488-­2. 6. Affoo RH, et al. Meta-analysis of salivary flow rates in young and older adults. J Am Geriatr Soc. 2015;63:2142–51. https://doi.org/10.1111/jgs.13652. 7. Buzalaf MAR, Hannas AR, Kato MT.  Saliva and dental erosion. J Appl Oral Sci. 2012;20:493–502.

4  Saliva and Tooth Wear

45

8. Pedersen AML, Sørensen CE, Proctor GB, Carpenter GH. Salivary functions in mastication, taste and textural perception, swallowing and initial digestion. Oral Dis. 2018;24:1399–416. https://doi.org/10.1111/odi.12867. 9. Lourenço M, Azevedo A, Brandão I, Gomes PS. Orofacial manifestations in outpatients with anorexia nervosa and bulimia nervosa focusing on the vomiting behavior. Clin Oral Invest. 2018;22:1915–22. https://doi.org/10.1007/s00784-­017-­2284-­y. 10. Saleh J, et al. Salivary hypofunction: an update on aetiology, diagnosis and therapeutics. Arch Oral Biol. 2015;60:242–5. 11. Watanabe S, Dawes C. The effects of different foods and concentrations of citric acid on the flow rate of whole saliva in man. Arch Oral Biol. 1988;33(1):1–5. 12. Liu J, Duan Y. Saliva: a potential media for disease diagnostics and monitoring. Oral Oncol. 2012;48:569–77. 13. van Nieuw Amerongen A, Bolscher JGM, Veerman ECI. Salivary proteins: protective and diagnostic value in cariology? Caries Res. 2004;38:247–53. https://doi.org/10.1159/000077762. 14. Neyraud E. Saliva: secretion and functions. In: Ligtenberg AJM, Veerman ECI, editors. Saliva: secretions and functions, vol. 24. Basel, Karger: Monogr Oral Sci; 2014. p. 61–70. https://doi. org/10.1159/000358789. 15. Hara AT, Zero DT.  The potential of saliva in protecting against dental erosion. In: Lussi A, Ganss C, editors. Erosive tooth wear, vol. 25. Basel, Karger: Monogr Oral Sci; 2014. p. 197–205. https://doi.org/10.1159/000360372. 16. West NX, Joiner A. Enamel mineral loss. J Dent. 2014;42SI:S2–S11. 17. Loke C, et  al. Factors affecting intra-oral pH—a review. J Oral Rehabil. 2016;43:778–85. https://doi.org/10.1111/joor.12429. 18. Shellis RP, et al. Understanding the chemistry of dental erosion. In: Lussi A, Ganss C, editors. Erosive tooth wear, vol. 25. Basel, Karger: Monogr Oral Sci; 2014. p.  163–79. https://doi. org/10.1159/000359943. 19. Lussi A, et al. Dental Erosion—an overview with emphasis on chemical and histopathological aspects. Caries Res. 2011;45(Suppl. 1):2–12. https://doi.org/10.1159/000325915. 20. Moazzez RV, et al. Comparison of the possible protective effect of the salivary pellicle of individuals with and without erosion. Caries Res. 2014;48:57–62. https://doi.org/10.1159/000352042. 21. Hannig C, et al. Protective effect of the in situ pellicle on dentin erosion—an ex vivo pilot study. Arch Oral Bio. 2007;52:444–9. 22. Hannig M, Hannig C. The pellicle and erosion. In: Lussi A, Ganss C, editors. Erosive tooth wear, vol. 25. Basel, Karger: Monogr Oral Sci; 2014. p. 206–14. 23. Carvalho TS, et al. Consensus report of the European Federation of Conservative Dentistry: erosive tooth wear – diagnosis and management. Clin Oral Invest. 2015;19:1557–61. https:// doi.org/10.1007/s00784-­015-­1511-­7. 24. Shellis RP, Addy M. The interactions between attrition, abrasion and erosion in tooth wear. In: Lussi A, Ganss C, editors. Erosive tooth wear, vol. 25. Basel, Karger: Monogr Oral Sci; 2014. p. 32–45. https://doi.org/10.1159/000359936. 25. Young WG, Khan F. Sites of dental erosion are saliva-dependent. J Oral Rehab. 2002;29:35–43. 26. Shirlaw PJ, Khan A. Oral dryness and Sjogren’s: an update. BDJ. 2017;223:649–54. 27. Kielbassa AM, et al. Radiation-related damage to dentition. Lancet Oncol. 2006;7:326–35. 28. Bhandari S, et  al. Radiotherapy-induced oral morbidities in head and neck cancer patients. Spec Care Dentist. 2020;40:238–50. https://doi.org/10.1111/scd.12469. 29. Jensdottir T, et  al. Saliva in relation to dental erosion before and after radiotherapy. Acta Odontol Scand. 2013;71:1008–13. https://doi.org/10.3109/00016357.2012.741704. 30. Ribeiro Santiago P, Song Y, Hanna K, Nair R.  Degrees of xerostomia ? A Rasch analysis of the xerostomia inventory. Community Dent Oral Epidemiol. 2020;48:63–71. https://doi. org/10.1111/cdoe.12504. 31. Wetselaar P, et  al. Associations between tooth wear and dental sleep disorders: a narrative overview. J Oral Rehabil. 2019;46:765–75. https://doi.org/10.1111/joor.12807. 32. Tulek A, et al. Dental erosion in mice with impaired salivary gland function. Acta Odontol Scand. 2020; https://doi.org/10.1080/00016357.2020.1734234.

46

R. Sambrook

3 3. Navazesh M, Kumar SKS. Measuring salivary flow. JADA. 2008;139(Suppl. 5):35S–40S. 34. Ramsay et al. Tooth wear and the role of salivary measures in general practice patients. Clin Oral Invest 2015;19:85–95. DOI: https://doi.org/10.1007/s00784-­014-­1223-­4. 35. Lofgren CD, et al. A systematic review of methods to diagnose oral dryness and salivary gland function. BMC Oral Health. 2012;12:29. 36. Lussi A, Schaffner M. Progression of and risk factors for dental erosion and wedge-shaped defects over a 6 year period. Caries Res. 2000;34:182–7. 37. Correa MCCSF, et al. Salivary parameters and teeth erosions in patients with gastroesophageal reflux disease. Arq Gastroenterol. 2012;49:214–8. 38. Hopcraft MS, Tan C.  Xerostomia: an update for clinicians. Aust Dent J. 2010;55:238–44. https://doi.org/10.1111/j.1834-­7819.2010.01229.x. 39. Sun K, et al. Tooth wear: a cross-sectional investigation of the prevalence and risk factors in Beijing, China. BDJ Open. 2017;3:16012. https://doi.org/10.1038/bdjopen.2016.12. 40. WHO Media Briefing. Available from: https://www.who.int/dg/speeches/detail/who-­director-­ general-­s-­opening-­remarks-­at-­the-­media-­briefing-­on-­covid-­19%2D%2D-­11-­march-­2020. Accessed 9th November 2020. 41. WHO Covid Dashboard. Available from: https://covid19.who.int/ Accessed 9th November 2020. 42. Pedrosa M, Sipert CR, Nogueira FN.  Salivary glands, saliva and oral presentations in COVID-19 infection. SciELO. 2020;20 https://doi.org/10.1590/pboci.2020.112. 43. Farshidfar N, Hamedani S.  Hyposalivation as a potential risk for SARS-CoV-2 infection: Inhibitory role of saliva. Oral Dis. 2020;00:1–2. https://doi.org/10.1111/odi.13375. 44. Chen L et al. Detection of 2019-nCoV in Saliva and Characterization of Oral Symptoms in COVID-19 Patients (March 14, 2020). Available at SSRN: https://ssrn.com/abstract=3557140 or https://doi.org/10.2139/ssrn.3557140 45. Sinjari B, et al. SARS-CoV-2 and oral manifestation: an observational, human study. J Clin Med. 2020;9:3218. https://doi.org/10.3390/jcm9103218. 46. Saniasiaya J.  Xerostomia and COVID-19: unleashing Pandora’s Box. Ear Nose Throat J. 2021;100(Suppl. 2):139S. https://doi.org/10.1177/0145561320960353. 47. Fantozzi PJ, et al. Xerostomia, gustatory and olfactory dysfunctions in patients with COVID-19. Am J Otolaryngol. 2020;41:102721. https://doi.org/10.1016/j.amjoto.2020.102721. 48. Biadsee A, et al. Olfactory and Oral Manifestations of COVID-19: sex-related symptoms— a potential pathway to early diagnosis. Otolaryngol Head Neck Surg. 2020; https://doi. org/10.1177/0194599820934380. 49. Fini MB. Oral saliva and COVID-19. Oral Oncol. 2020;108:104821. https://doi.org/10.1016/j. oraloncology.2020.104821. 50. Almqvist J, et al. Neurological manifestations of coronavirus infections—a systematic review. Ann Clin Transl Neurol. 2020;7(10):2057–71. https://doi.org/10.1002/acn3.51166.

5

Feeding and Eating Disorders: Behaviours That Adversely Impact Oral Health Alex Milosevic and Fatemeh Amir-Rad

Abbreviations AN BED BN DMFS DMFT DSM ED EDNOS GORD HRQoL ICD OR OSFED QoL RD SF-36 SIV

Anorexia nervosa Binge eating disorder Bulimia nervosa Decayed, missing and filled tooth surfaces Decayed missing and filled teeth Diagnostic and statistical manual of mental disorders Eating disorders Eating disorder not otherwise specified Gastro-oesophageal reflux disease Health-related quality of life International classification of diseases Odds ratio Oher specified feeding or eating disorder Quality of life Rumination disorder Medical outcome study—short form 36 Self-induced vomiting

A. Milosevic (*) · F. Amir-Rad Department of Prosthodontics, Hamdan Bin Mohammed College of Dental Medicine, Mohammed Bin Rashid University (MBRU), Dubai, UAE e-mail: [email protected] © Springer Nature Switzerland AG 2022 A. Eder, M. Faigenblum (eds.), Tooth Wear, BDJ Clinician’s Guides, https://doi.org/10.1007/978-3-030-86110-0_5

47

48

5.1

A. Milosevic and F. Amir-Rad

Introduction

There has been considerable progress regarding the understanding and classification of eating disorders since the publication of the first review of eating disorders and the dentist in 1999 [1]. Dentists and oral health care professionals are likely to see individuals with an eating disorder at some point in a practicing lifetime. Understanding the classification, psychological background, medical co-­morbidities and oro-dental manifestations of the eating disorders should improve the overall quality of care provided by the dental team. This chapter aims to provide a narrative review of these disorders.

5.2

Classification, Diagnostic Criteria and Epidemiology

The eating disorders have been classified in several iterations of the American Psychiatric Association Diagnostic and Statistical Manual of Mental Disorders. Its 5th Edition (DSM-V) replaced DSM-IV in 2013 and the World Health Organisation (WHO) revised its International Classification of Diseases (ICD-10) to the current ICD-11 [2, 3]. In DSM-V, pica and rumination appear under ‘Feeding and eating disorders’ and Binge Eating Disorder (BED) is recognised as a separate disorder with the intention to reduce the number of diagnoses within the ‘Eating disorder not otherwise specified’ or EDNOS category. Studies have suggested that a significant number of patients categorised with EDNOS may actually have BED [4]. Researchers in the field believed that improved utility and validity would result from the new classification but emphasised that categorical classification was limiting as mental disorders represent a spectrum [5]. An additional dimensional component to diagnostic criteria such as frequency of binge eating was advocated. DSM-V, therefore, includes anorexia nervosa (AN), bulimia nervosa (BN), binge eating disorder (BED), pica, rumination disorder (RD), avoidant/restrictive food intake disorder (ARFID), and the ‘eating disorder not otherwise specified’ (EDNOS) category, renamed ‘other specified feeding or eating disorder’ (OSFED). These DSM-V distinct diagnoses are shown in Table 5.1. There are two subtypes of AN, restricting type and binge-eating/purging type. The lifetime prevalence of AN is 0.5–2% and for BN it is between 0.9% and 3% [6, Table 5.1  DSM-IV compared to DSM-V eating disorders’ diagnoses DSM-IV Pica Rumination disorder Feeding disorder of infancy or early childhood Anorexia nervosa Bulimia nervosa

DSM-V Pica Rumination disorder Avoidant/restrictive food intake disorder Anorexia nervosa Bulimia nervosa Binge eating disorder Eating Disorder Not Otherwise Specified (EDNOS) Other specified feeding or eating disorder Unspecified feeding or eating disorder

5  Feeding and Eating Disorders: Behaviours That Adversely Impact Oral Health

49

7]. The peak age of onset for AN is from 13 to 18 years of age and for BN it is 16–17 years [8, 9]. BED is characterised by eating abnormal amounts of food in a short period of time and is associated with being overweight and obesity. Males are more likely to have BED than AN or BN. From an individual perspective, however, eating disorders tend to evolve over time. In the early stages, individuals are successful in controlling their eating and lose weight but as years pass, control is lost and binge eating develops. Thus, sufferers often proceed from a diagnosis of anorexia to bulimia to a mixed state [5]. Because thresholds for the various eating disorders have been reduced, prevalence rates have increased [10]. A recent meta-analysis of seven studies that met the inclusion criteria reported the estimated lifetime prevalence of any eating disorder to be 1.01% (95% CI 0.54, 1.89) [10]. For each ED, BED was highest (2.22%) followed by BN (0.81%) and AN (0.03%) [10]. In a group of 496 adolescent American school girls, the overall lifetime prevalence for any eating disorder by age 20 years was reported to be 13.1% with the earliest peak age of onset for BN at 16 years [11]. AN, however, has a much lower prevalence in Africa, Latin America and among Hispanics/ Latinos in the USA because higher body weight and a curvaceous shape are idealised [12]. These conditions are global with different cultural manifestations.

5.3

Pica and Rumination Disorders

Pica is the chewing and ingestion of non-nutritive substances for at least 1 month at an age for which this behavior is developmentally inappropriate. These disorders are more commonly seen in children, pregnant females and in institutionalised individuals or those with learning disabilities. The substances can include chalk, clay, coal, grass, hair, soil, stones, paper, metal, cigarette butts, sand and soap with the term, geophagia, being specific for the ingestion of soil or clay [13–16]. Ryzophagia is the ingestion of uncooked rice seen in females from Pakistan and India [17]. Pica, and particularly geophagia, has been regarded as normal practice in certain tribal societies and cultures [16]. Hunger is not usually associated with pica or geophagia but nutritional deficiencies such iron-deficiency anaemia have been linked. For instance, anaemia during pregnancy and the cravings to chew non-nutritive substances such as coal may be related. Interestingly, pregnant and lactating bats ingest clay either to supplement high mineral demand or to buffer toxic or carcinogenic plant metabolites and was postulated as the most likely explanation for geophagy in primates and large mammals [18]. Pica has been reported in 20% of pregnant women who are more likely to be black, live in rural areas and have a positive family history of pica [19]. The medical consequences of pica can be severe. Toxicity includes lead poisoning from ingestion of soil or lead-based paint, mercury poisoning from paper pica, hypokalemia from eating match heads or clay [20–22]. Parasitic infections, electrolyte disturbances, intestinal obstruction, perforation and peritonitis have also been reported in the literature [16, 23]. Mortality can be high [16]. Iron deficiency and microcytic anaemia have often been reported but whether this is cause or effect of pica is unknown [15].

50

A. Milosevic and F. Amir-Rad

5.3.1 Oral Manifestations of Pica Abraded or worn teeth have resulted from pica [13, 15, 17, 24]. Independent case reports of a 36-year-old female who chewed sand and a 56-year-old female who chewed grit and stones show extensive wear through to dentine [13, 15]. Sharp and jagged PFM crowns were evident with fractured ceramic. Interestingly both cases had good periodontal status but the authors did not speculate whether the abrasivity of the pica substances or if increased salivary flow from mastication contributed to plaque removal or acid buffering. A 7-year-old girl in India was reported to have eaten and ingested pieces of brick for 5 years and presented with iron and zinc deficiencies as well as severe ‘attrition’ [24]. Since attrition is direct tooth-to-tooth wear, it is more likely the authors meant abrasion although tooth wear is a more appropriate diagnostic term as both may have occurred. Pica is a rare behavior in the general population but should be considered in certain high-risk groups such as pregnant females, people from developing countries where malnutrition is common and institutionalized individuals. Patients with tooth wear secondary to pica, however, may be embarrassed and thus secretive about the habit. Careful and sensitive questioning will apply to all patients if the aetiology of the tooth wear is unexplained and these behaviours are suspected.

5.3.2 Rumination Disorder Rumination disorder is the same as rumination syndrome and is characterised by post-prandial retrograde flow of gastric content into the mouth followed by re-­chewing, re-swallowing or spitting out [25]. Classification and diagnostic guidelines have proved problematic because of a lack of research, the heterogenous features and overlap with gastro-oesophageal reflux disease (GORD), gastroparesis and bulimia. Its diagnostic criteria, however, were unchanged in DSM-­V. Consequently, prevalence data are limited and it remains rare although it is seen more frequently in institutionalised individuals and those with learning difficulties (10%) [26]. Precursor stressful life events have been implicated (e.g. surgery) but it is unclear if rumination disorder is a psychiatric disorder or a manifestation of a physiological disturbance or both with primary factors and secondary maintenance mechanisms [27]. Nonetheless, rumination is believed to be primarily a behavioral problem involving chest expansion, voluntary contraction of the abdominal wall musculature and diaphragmatic relaxation resulting in raised intra-gastric pressure but reduced intra-thoracic pressure. The voluntary nature differs to GORD which is involuntary. Furthermore, rumination can be concurrent with pica and can also occur in secret. It has been reported that sufferers experience protracted symptoms as a result of delay in accurate diagnosis [27].

5  Feeding and Eating Disorders: Behaviours That Adversely Impact Oral Health

51

Management involves diaphragmatic breathing, cognitive behavioural therapy, aversion therapy and medication. Among the latter, the anti-spasmodic muscle relaxant Baclofen resulted in reduced frequency of regurgitation compared with a placebo whilst other medication such as Proton Pump Inhibitors and anti-emetics have little or no effect [28]. Surgery in the form of fundoplication, the wrapping of the upper part of the stomach around the lower oesophagus, is beneficial for GORD, but not for rumination which is regarded primarily as a psychological disturbance. Dental erosion was associated with rumination syndrome in age- and sex-­ matched children compared to healthy controls [29]. Although the authors did not state the odds ratios, 77% of ruminating children of mean age 10 years had erosion compared to 13% in the control group. A further finding was that caries experience was the same between the two groups [29]. Rumination in a 16-year-old female with an eating disorder was successfully managed by chewing gum as was a 6-year-­ old autistic boy, who had five teeth extracted for ‘decay’, with a reported subsequent improvement in dental health [30, 31]. Halitosis was the main reason for referral to a gastroenterology clinic in series of 9 ruminants with 3 generations of one family being represented [32]. Dental erosion has been described in institutionalised and healthy adults who ruminated [33, 34]. The distribution of the erosion is, however, more generalised than that seen after vomiting as it involves the occlusal surfaces and especially the lower buccal surfaces as gastric contents are held in the buccal pouch [34]. Attrition from stress related bruxism may be superimposed as this parafunctional habit is common in institutionalised individuals. Erosive wear may be an appropriate term if acid erosion is the primary aetiological factor although the term tooth wear encompasses all processes resulting in cumulative surface loss [35].

5.4

Anorexia Nervosa

Anorexia primarily affects adolescent girls and young women. It is characterised by distorted body image, excessive dieting and a pathological fear of becoming fat that leads to severe weight loss. Starvation accounts for many of the physical signs and symptoms. Being more than 15% below normal weight for age and gender with no underlying medical condition to account for this is diagnostic (Table 5.2). The criterion of amenorrhoea or the absence of at least three menstrual cycles in the previous DSM-IV classification has been removed as it cannot apply to males, pre-menarchal or post-menopausal females and those taking the oral contraceptive pill. Of the eating disorders, anorexia has the lowest overall lifetime prevalence of up to 1% depending on study, although prevalence is highest in Western countries and in female adolescents. The incidence of AN in Western Europe is approximately 5 new cases per 100,000 for each decade from the 1970’s up to and including 2000–2009 [12]. AN remains a relatively rare condition. The female to male ratio is 5:1.

52

A. Milosevic and F. Amir-Rad

Table 5.2  Diagnostic criteria for DSM-V eating disorders Eating disorder Anorexia nervosa Bulimia nervosa

Binge eating disorder

5.5

BMI 75% of time over 3 months Pre-occupation with shape and weight Minimum of 4 uncontrollable binge-eating episodes per month for at least 3 months Minimum of 4 compensatory behavior episodes per month for at least 3 months Weight and shape a definite aspect of self-evaluation Minimum of 4 uncontrollable binge-eating episodes per month for at least 3 months Less than one compensatory behavior on average per month during this period Marked distress regarding bingeing Binge eating characterized by 3 or more of the following:    rapid eating    eating until uncomfortably full    eating large amounts when not hungry    eating alone because of embarrassment    feeling disgusted, depressed or guilty after overeating

Bulimia Nervosa

Bulimia involves at least one episode of binge eating per week (DSM-V) followed by compensatory behaviours that include self-induced vomiting (SIV) and misuse of laxatives or diuretics. The mean age of onset was reported to be 20.6 years in the WHO mental health survey and the incidence has been reported as 12 per 100,000 per year [36, 37]. The presentation of an individual with BN can vary from underweight to overweight in contrast to AN where underweight is typical. For a diagnosis of bulimia to be made, at least 4 binge- eating episodes must occur (Table 5.2) but not all bulimics compensate by vomiting. Some will use laxatives, diuretics, fast and/or over-exercise. The potential effects of these compensatory methods are discussed later. Self-reported data collected from bulimic subjects on their behaviours is inevitably limited and possibly inaccurate and thus an underestimate because of the shame associated with their activities [38]. It is known that individuals with an ED may hide this by becoming an athlete or conversely, enter a sport healthy but develop an ED whilst training. The term, anorexia athletica, is given to athletes with reduced energy intake and reduced body mass despite high physical performance but who do not meet the diagnostic criteria of AN or BN [39]. The female athlete triad of disordered eating, amenorrhoea and osteoporosis is well recognised but males can be affected also [40]. Some athletes may progress to anorexia or bulimia especially in individual rather than team sports or in sports with weight categories (rowing, boxing), aesthetic sports (gymnastics, figure skating) or anti-gravitational sport (high jump) [41].

5  Feeding and Eating Disorders: Behaviours That Adversely Impact Oral Health

5.6

53

Binge Eating Disorder

Binge eating is defined as recurrent episodes of excessive food intake in a short period of time, usually within 2-hours, followed by feelings of guilt, embarrassment or disgust. Bingeing can be a private or secretive act with a sense of lack of control during the binge (inability to stop) which results in the consumption of large quantities of food, beyond mere overeating. It occurs at least once a week over 3 months and prior hunger is not present. The episodes are characterised by rapid eating until becoming uncomfortable followed by self-loathing or depression. Unlike bulimia, compensatory behaviours such as purging are not a feature. Obesity is common although sufferers are not overly concerned with body image or shape. The gender distribution is roughly 50:50.

5.7

 ental health, Behavioural and Medical Complications M Related to Eating Disorders (ED)

Common psychiatric disorders in ED patients are depression, anxiety, obsessive-­ compulsive disorder, post-traumatic stress disorder, personality disorders, substance abuse disorders, and self-injurious behaviours [42, 43]. Depression is common in AN with a lifetime prevalence of 50–68%, and anxiety disorder prevalence ranges from 30% to 65%. In BN, the lifetime prevalence of mood disorders and anxiety disorders is 50–70% and 13–65% respectively [44]. A meta-analysis reported high mortality rates for individuals with an ED with AN having the highest rates of at least 5–6%, with a common cause of death being suicide [45, 46]. The mortality rates for BN and EDNOS are lower and comparable [45]. Dieting often precedes an eating disorder and when dieting fails to achieve the desired weight loss, feelings of diminished self-esteem and loss of control develop, with progression to an eating disorder. This deepens the sense of guilt and compounds the low self-esteem resulting in a downward spiral of food restriction and increasing physical, mental and medical problems. Alternatively, because sufferers especially with AN feel unable to control external pressures, successful control of food intake is empowering. EDs can affect many organ systems and medical complications can occur at any weight. Purging may be present in AN and BN and is the defining feature of purging disorder, an eating disorder identified as part of OSFED [2]. Up to 86% of ED sufferers engage in self-induced vomiting (SIV), although laxative and diuretic misuse are also common methods of purging [47–49]. Due to the young age of onset and the extreme nutritional restrictions, AN can lead to significant developmental concerns. The rate of growth does not meet expectations and bone mineral density is low [50]. Common findings include hypotension, hypothermia, and bradycardia, anaemia, leukopenia, elevated urea nitrogen and hepatic enzymes [51–53]. The medical complications of EDs are shown in Table 5.3.

54

A. Milosevic and F. Amir-Rad

Table 5.3  Medical complications of eating disorders Organ system AN Cardiovascular Bradycardia and hypotension Mitral valve prolapse Sudden death (related to QT prolongation) Peripheral oedema Refeeding syndrome Dermatologic Dry skin Carotenodermia Lanugo hair Starvation-associated pruritis GI Constipation Refeeding pancreatitis Acute gastric dilatation due to refeeding

Endocrine and metabolic

Hematologic

Pulmonary/ mediastinal

Amenorrhea Infertility Osteoporosis Thyroid abnormalities Hypercortisolemia Hypercholesterolemia due to impaired cholesterol metabolism Hypoglycemia Neurogenic diabetes insipidus Impaired temperature regulation Fluid and electrolyte abnormalities Pancytopenia due to starvation Decreased erythrocyte sedimentation rate –

After Walsh JME, Wheat ME, Freund K [53]

BN Arrhythmias Diet pill toxicity Palpitations Hypertension Emitine cardiomyopathy Mitral valve prolapse

BED Hypertension secondary to obesity Hyperlipidemia secondary to diet and obesity

–

Diabetic skin changes Skin changes due to morbid obesity

Dental erosion Parotid enlargement Oesophageal rupture Gastro-oesophageal reflux due to chronic relaxation of sphincter Acute gastric dilatation After-binge pancreatitis Constipation due to laxative abuse Cathartic colon Irregular menses Hypoglycemia Mineralocorticoid excess Electrolyte imbalances Dehydration Nephropathy

Bloating Abdominal pain

–

–

Diabetes due to obesity

Aspiration pneumonitis – Pneumo-mediastinum with weight loss or precipitated by vomiting Pneumothorax or rib fractures

5  Feeding and Eating Disorders: Behaviours That Adversely Impact Oral Health

55

Several severe medical complications associated with food restriction, SIV, laxative and diuretic use were described by Forney et al. [54] and include cardiac arrest, rectal prolapse, renal failure and musculoskeletal effects (e.g. rhabdomyolysis). Hypokalemia and hypophosphatemia are common in patients with SIV and laxative abuse. Malnutrition causes delayed gastric emptying, constipation, dyslipidemias and mild transaminitis which is the elevation of liver enzymes indicative of inflammation or damage to liver cells [55, 56]. Vomiting can result in oesophagitis and in serious cases, oesophageal rupture [57]. Anorexics usually report abdominal bloating and nausea whilst BED sufferers are at risk of gastric dilation [58]. Patients with AN are at risk of refeeding syndrome, the potentially fatal shift in fluids and electrolytes that may happen in malnourished patients receiving artificial refeeding. The hallmark biochemical feature of this syndrome is hypophosphatemia [59]. ED patients presenting to primary care complain of fatigue, cold intolerance, menstrual irregularity and gastrointestinal issues such as abdominal pain and constipation [60]. Whereas dehydration from misuse of laxatives or restricting fluid intake are the major reported reasons for ED patients being seen in hospital emergency departments [61]. Eating disorder risk has been associated with alcohol and drug use. Cocaine, heroin, amphetamines, excess alcohol intake and cigarette smoking are ways that individuals with an ED control their appetite or weight [62]. The prevalence of caffeine use and cigarette smoking are higher in people with EDs compared to individuals without EDs [63–65]. Older females with ED may develop severe osteoporosis, cardiomyopathy leading to a sudden cardiac death, muscle loss and gastroesophageal reflux disease [66]. Patients with AN usually have hypothalamic suppression with low sex hormone levels. Females with AN may have pubertal delay, pubertal regression, and menstrual dysfunction [67]. Anorexics may have fine facial and body hair called lanugo, amenorrhea and display mood disturbances. The presence of calluses on the knuckles or back of the hand, Russell’s sign, caused by scraping of the back of the hand against the upper teeth to induce vomiting is seen much less than previously estimated (Fig. 5.1) [68, 69]. Subconjunctival haemorrhages are another observable consequence associated with self-induced vomiting [70].

5.8

Quality of Life in the Eating Disorders

The concept of health-related quality of life (HRQoL) includes physical, mental, emotional and social aspects of general quality of life that can be distinctly shown to affect health [71] (Chaps. 1 and 9). The assessment of QoL in ED patients is important in order to predict clinical outcomes and the possibility of relapse and recurrence [72]. The most popular measure used to assess HRQoL was the Medical Outcome Study Short Form 36 [SF-36] and Short Form 12 [SF-12] which are widely used patient-report tools. A recent meta-analysis of seven studies that met the

56

A. Milosevic and F. Amir-Rad

Fig. 5.1  Callus on the back of the hand (Russell’s sign) in a 37-year-old male with a history of bulimia nervosa of 20 years’ duration

inclusion criteria reported a significantly lower HRQoL in all EDs compared to a population mean but it was not possible to establish any differences between the diagnostic groups [73]. A subsequent systematic review on the HRQoL in patients with AN, BN and BED included 41 studies using various QoL questionnaires [74]. The study reported that HRQoL in AN, BN and BED was significantly lower than in the general population and was particularly manifest in the mental component of the quality of life. Several studies in this systematic review could not reach a conclusion regarding the relative effects of each ED on HRQoL because a low QoL is associated with depression and anxiety which are common in all EDs [74–78]. Furthermore, the systematic review also found that obesity was correlated with lower QoL in patients with BED [79–82]. This was also the case among obese BED patients when compared to non-BED subjects [83]. Findings of a recent study by Hart et al. [84] indicate that during young adulthood eating behaviors and ED diagnoses are associated with considerable declines in HRQoL. This study also demonstrated that high or very low body weight in individuals with EDs leads to further reduction in HRQoL [84]. Interestingly, the HRQoL of siblings and carers of AN, BN, and BED patients was similarly noted to be diminished in some of the studies [85–88]. The HRQoL was still severely impaired in 101 subjects with either AN or BN after 8 years despite significant improvement in Body Mass Index with the authors concluding that there was a long-lasting impact on quality of life even after symptom remission [89]. Low self-esteem contributed most to QoL in 56 ED patients and 148 former ED patients [90]. Chronic illness is generally believed to be more troublesome and difficult to manage but ED illness duration was not related to QoL because of adaptation to functional impairment, termed response shift [91]. Nonetheless there was a greater degree of functional impairment in binge-purge spectrum diagnoses and especially in treatment seeking participants with bing-purge subtype AN [91]. In summary, QoL is significantly impaired in the EDs and lower than in the general population. Co-morbidities such as anxiety and depression will influence ability to cope with everyday life. Unfortunately, poor QoL can last for a prolonged period even after resolution of the eating disorder.

5  Feeding and Eating Disorders: Behaviours That Adversely Impact Oral Health

5.9

57

Oro-Dental Features

The initial reports of the impact of eating disorders on oral health pre-date classification and recognition of bulimia as a separate entity [92, 93]. These early studies identified acid erosion secondary to vomiting and a high intake of acidic drinks. Fresh fruit, which is potentially erosive, was eaten to induce diarrhoea. Oral health professionals are in a unique position to identify patients with EDs and refer for medical and psychological care. Most oral manifestations in ED sufferers result from chronic vomiting, nutritional deficiencies and poor diet with high sugar intake, ineffective oral hygiene, underlying psychological disturbances and drug use [94, 95].The potential oro-dental features are shown in Table 5.4.

5.9.1 Dental Erosion Dental erosion is a common oral manifestation in individuals who practice self-­ induced vomiting and may progress rapidly in ED patients resulting in cold-induced hypersensitivity, aesthetic impairment and interruption to daily life [96–98]. Dental erosion is clinically detectable as loss of luster, thin enamel with chamfered ridges and cupping of cusps often with exposed dentine (Fig. 5.2a–c) [99, 100]. Many studies report that eroded teeth occur more frequently in subjects that vomit compared to those that do not although it must be borne in mind that the earlier studies used DSM-III and DSM-IV criteria [101–118]. Usually, both the severity and the number of eroded teeth increase with duration of SIV. The association, however, between frequency, duration of vomiting and dental erosion is not always clear cut as long-term ED sufferers, some of whom vomited over 10 years, did not exhibit dental erosion [104, 112, 113]. One methodological problem is the wide variety of indices used to measure presence and/or severity of erosion, some applied to casts, not to mention confounding with attrition and/or abrasion. Threshold criteria or cut-off points vary for degrees of severity which make comparison of results difficult. Nonetheless, most studies report that erosion occurs most commonly on the occlusal surfaces of molars and palatal surfaces of anterior maxillary teeth [104, 112, 113]. With prolonged vomiting, buccal and palatal surfaces of posterior teeth may also be affected [113]. Table 5.4  Possible oro-dental manifestations of feeding and eating disorders Dental erosion Caries and microbiological change Saliva

 •  Including hypersensitivity  •  Including halitosis  •  Including parotid gland enlargement, increased salivary viscosity, reduced salivary flow or xerostomia

Periodontal disease Soft tissue lesions  •  Mucosal trauma—ecchymosis Temporomandibular disorders Abrasion  •  Secondary to pica

58

a

A. Milosevic and F. Amir-Rad

b

c

Fig. 5.2 (a) Frontal view of a bulimic patient with shortened maxillary incisors secondary to erosion affecting the palatal surfaces. The gingivae appear healthy although there is evidence of gingival trauma in the lower left quadrant and early recession in a 26-year-old female. (b) Maxillary occlusal view of the same patient with marked palatal erosive wear. (c) Severely eroded palatal surfaces are evident. It is not known if the ceramic crowns on the incisors pre-date the erosion, but it is likely that SIV continued after they were placed

Two recent systematic reviews and meta-analyses, published in 2014 and 2015, have determined summary estimates of the odds of having dental erosion from vomiting [119, 120]. Hermont et al (2014) presented 12 outcomes and found that combined EDs had a significant association with dental erosion with a Summary Odds Ratio (OR) of 12.4 (95% CI, 4.1–37.5) [119]. Anorexia, bulimia and bulimia with SIV were all strongly associated with erosion but bulimia without SIV had the lowest odds. The authors reported that heterogeneity was high and the wide CIs indicate imprecision in interpreting the effect size. Kisely et al analysed 10 studies that met the inclusion criteria and reported that ED subjects had five times the odds of dental erosion (95% CI 3.31–7.58) when compared to controls [120]. The summary odds ratio estimate for EDs with SIV was 7.32 and for ED without SIV it was 3.10 which was significantly greater than control groups [120]. These two studies support the link between vomiting and erosion despite the high risk of bias in observational studies. Once dentine becomes exposed, sensitivity may occur. Drinking water before vomiting is thought to dilute gastric content and neutralise the acidity of vomitus, thereby reducing the development of dental erosion [121]. Studies showed that tooth brushing immediately after vomiting or eating acidic foods is harmful and is associated with dental erosion [112, 121, 122]. Thus, post-­ vomiting oral hygiene should include thorough oral rinsing with water or fluoridated mouth rinse to neutralise acid in the oral cavity and to promote remineralisation before careful brushing.

5  Feeding and Eating Disorders: Behaviours That Adversely Impact Oral Health

59

Excessive consumption of highly acidic foods and drinks may cause further erosion of the buccal or facial surfaces of teeth [105]. This is specifically seen in patients with AN who consume raw citrus fruits to maintain their low-calorie diets [121]. Clearly, vomiting and any acidic drinks are common risks for dental erosion but it should be noted that carbonic acid in carbonated drinks does not contribute to erosion as it is a very weak acid. Citric and phosphoric acids are the acids in drinks likeliest to cause erosion. Few studies on erosion in EDs have controlled for confounding factors such as acidic drinks.

5.9.2 Caries and Oral Microbiology Patients with ED rely on sugar consumption as an important source of calories and are thus very susceptible to caries. Sudden cessation of sweet food and drink intake may, however, increase morbidity [122]. Therefore, behaviour modification and reduction of sugar intake should be discussed to prevent possible complications. Carbohydrate intake was high in a group of vomiting bulimics [123]. Caries experience, expressed as either DMFT or DMFS, in EDs compared to healthy controls has been assessed in several studies with conflicting results. No difference in caries experience was found between ED subjects and healthy controls [63, 103, 104, 107, 114, 124, 125]. Whereas others report more caries present in the EDs [106, 109]. ED subjects had significantly more caries than controls according to the four studies in the systematic review [120], despite perfectionism and obsessive-compulsive traits being common in EDs [126]. The risk of caries is increased by the prescription of medication such as dextrose tablets and sucrose-containing vitamin C drinks [127]. Overall, caries is not specifically associated with EDs despite the reported high intake of regular (non-diet) acidic drinks. In parallel with caries experience, the oral flora has also been examined in the EDs. A repeatedly low intra-oral pH from SIV should theoretically favour a more aciduric microbiota. The prevalence of salivary Streptococcus (S.) mutans, S. sobrinus, lactobacilli and yeasts was reported to be higher in patients with BN compared to those without BN [128]. However, counts of salivary S. mutans and lactobacillus species were not significantly different between anorexics without ‘significant vomiting habits’ and controls [107]. The same result regarding lactobacillus species, S mutans and candida was reported by Rytömaa et al. and Johansson et al. (2012) in BN and combined EDs respectively [109, 115].

5.9.3 Saliva and Salivary Glands Uni- or bilateral parotid enlargement has been reported in the EDs with a higher prevalence of parotid ‘swelling’ compared to matched controls [115]. But there was no functional impairment on stimulated flow rate [115]. Parotid enlargement is believed to be specifically related to self-induced vomiting [129–132]. Others have

60

A. Milosevic and F. Amir-Rad

Fig. 5.3  Bilateral parotid enlargement, which was painless and episodic. Same patient as seen in Fig. 5.1

reported, however, that enlarged parotids are not a consistent feature of ED patients with self-induce vomiting [57]. Figure 5.3 shows the appearance of bilateral parotid enlargement in a male bulimic. Frequent vomiting or starvation can result in hypo-salivation [96]. One study found that patients with BN reported xerostomia more frequently and had lower unstimulated whole saliva flow rates than healthy controls but acknowledged that the bulimia group were on dry mouth inducing medication [112]. Conversely, buffering capacity and a lower unstimulated saliva flow in ED subjects was not significantly different to controls although total protein and aspartate in the unstimulated saliva were significantly higher in the ED group [133]. Somewhat confusingly, medication within the ED group was not correlated to unstimulated or stimulated saliva flow rates but in the controls a negative correlation was found between drug intake and unstimulated secretion [133]. In bulimic patients, a higher activity of salivary proteases, collagenase and pepsin was found in subjects with erosion compared to those without erosion [134]. Additionally, the pH drop at the tooth surface after consumption of an acidic drink was lower and the pH recovery took longer in patients with erosion [135]. The basis for salivary gland enlargement in the EDs is not fully understood. Co-morbidities associated with metabolic disturbance, such as dehydration and starvation in the EDs, may lead to alteration of salivary gland structure and function. The complex nature, medication, and wide range of chronicity and severity of EDs probably mean some subjects will suffer with dry mouth and be at increased risk of caries and erosion (Chap. 4).

5.9.4 Periodontal Disease Periodontal parameters such as plaque index, gingival bleeding and clinical attachment have all been investigated. Several studies found no difference in plaque, bleeding scores or attachment loss between anorexics, bulimics and controls [63, 102, 104, 105, 109, 117]. Less plaque or bleeding in the ED groups has also been

5  Feeding and Eating Disorders: Behaviours That Adversely Impact Oral Health

61

reported [106, 107, 115], whilst one study found no difference in gingivitis across ED groups and between EDs and controls but reported that periodontitis was more common among ED patients [118]. Ineffective plaque control is not specific to the EDs and the majority of studies found that there were no differences in periodontal parameters between EDs and healthy controls.

5.9.5 Soft Tissue Lesions Nutritional deficiencies, such as Vitamin C deficiency or scurvy, can lead to swollen, bleeding gums and glossitis can occur with nicotinamide deficiency. Few studies have assessed oral mucosa in the EDs. The effects of AN on the oral mucous membranes include stomatitis secondary to anaemia [136]. A 30-year-old female suffering from AN presented with a tongue abscess, dysphagia and angular stomatitis [136]. Dry and/or cracked lips, candidiasis and burning tongue were more prevalent in the EDs compared to controls [63, 115]. Case reports have described necrotising sialometaplasia and hard palate ulceration from trauma as a result of chronic self-induced vomiting [137–139]. A 30-year-old bulimic female presented with a large heamatoma in the hard palate as seen in Fig. 5.4 [1].

5.9.6 Temporomandibular Disorders (TMD) Frequent episodes of SIV have been hypothesised to cause dislocation or subluxation of the condyles as a result of extreme mouth opening [98]. The range of mouth opening and presence of joint clicks/crepitation were no different between 86 ED females and 50 healthy female students although ‘general muscular sensitivity’ on palpation was more prevalent in the ED group. Which muscles and the level of specificity was not discussed as responses to muscle palpation are subjective [140]. Reported symptoms of headache, facial pain, jaw tiredness, tongue thrust, globus and sleep disturbances were all significantly more prevalent among ED patients compared to controls [140]. The authors concluded that that ED patients have a Fig. 5.4  A palatal heamatoma in a bulimic female. Note the low caries activity

62

A. Milosevic and F. Amir-Rad

higher risk for TMD but the prevalence of bruxism, clicks, grating, locking, difficulty opening or pain on movement were no different [140]. Neither study mentions if the examiners were blinded to cases or controls. Further research is needed to determine the strength of association of EDs with TMD.

5.10 Managing Patients with an Eating Disorder Management involves a multi-disciplinary team and support should be provided for affected families as these disorders are very distressing. Many ED patients are unwilling to disclose having an eating disorder or see a dental professional because of anxiety and/or feelings of shame or guilt about their eating problems. The mean Dental Anxiety Scale score was significantly higher in Norwegian females with an ED than the mean score for a representative sample of Norwegian women [141]. Similar results were found in ED patients referred for minor oral surgery [142]. A survey conducted in the United States identified embarrassment (81.1%), shame (77.6%), awkwardness (67.2%) and fear (54.2%) as the barriers that prevented 201 BN patients talking to oral health professionals [143]. It is therefore important that all health care professionals adopt a sympathetic and non-judgmental approach to the management of patients with EDs [144].

5.11 Conclusion The consequences of an eating disorder are significant and can be life threatening. Recent NICE guidelines outline general principles of care, recommendations for treatment and specifically mention dental considerations in section 1.10.6 [145]. Practical online advice, help and support is available from several agencies in the UK and overseas, some of which are listed below. All dental care professionals should be aware of the various types of eating disorder and their impact on oro-­ dental health. With such awareness, appropriate advice and management will follow. Agencies and Charitable Organisations Providing Advice and Support: www.beateatingdisorders.org.uk www.anorexiabulimiacare.org.uk www.nhs.uk/conditions/eating-­disorders https://eating-­disorders.org.uk

References 1. Milosevic A. Eating disorders and the dentist. Br Dent J. 1999;186(3):109–13. https://doi. org/10.1038/sj.bdj.4800036. 2. American Psychiatric Association. Diagnostic and statistical manual of mental disorders (DSM-5®). Washington, DC: American Psychiatric Publishing; 2013. 3. World Health Organization. (2018). International statistical classification of diseases and related health problems (11th Revision). Retrieved from: https://icd.who.int/browse11/l-­m/en

5  Feeding and Eating Disorders: Behaviours That Adversely Impact Oral Health

63

4. Wilfley DE, Bishop ME, Wilson GT, Agras WS. Classification of eating disorders: towards DSM-V. Int J Eat Disord. 2007;40:S123–9. https://doi.org/10.1002/eat. 5. Fairburn CG, Cooper Z.  Eating disorders, DSM-5 and clinical reality. Br J Psychiatry. 2011;198:8–10. https://doi.org/10.1192/bjp.bp.110.083881. 6. Sigel E. Eating disorders. Adolesc Med State Art Rev. 2008;19(3):547–72. 7. Hoste RR, Labuschagne Z, Le Grange D. Adolescent bulimia nervosa. Curr Psychiatry Rep. 2012;14(4):391–7. 8. Weaver L, Liebman R.  Assessment of anorexia nervosa in children and adolescents. Curr Psychiatry Rep. 2011;13(2):93–8. 9. Sim LA, McAlpine DE, Grothe KB, Himes SM, Cockerill RG, Clark MM. Identification and treatment of eating disorders in the primary care setting. Mayo Clin Proc. 2010;85(8):746–51. 10. Qian J, Hu Q, Wan Y, Li T, Wu M, Ren Z, Yu D. Prevalence of eating disorders in the general population: a systematic review. Shanghai Arch Psychiatry. 2013;25(4):212–23. https://doi. org/10.3969/j.issn.1002-­0829.2013.04.003. 11. Stice E, Marti CN, Rohde P. Prevalence, incidence, impairment and course of the proposed DSM-5 eating disorder diagnoses in an 8-year prospective community study of young women. J Abnorm Psychol. 2013;122(2):445–57. https://doi.org/10.1037/a0030679. 12. Hoek HW. Review of the worldwide epidemiology of eating disorders. Curr Opin Psychiatry. 2016;29(6):336–9. https://doi.org/10.1097/YCO.0000000000000282. 13. Djemal S, Darbar UR, Hemmings KW. Case report: tooth wear associated with an unusual habit. Eur J Prosthodont Rest Dent. 1998;6(1):29–32. 14. Matson JL, Belva B, Hattier MA, Matson ML. Pica in persons with developmental disabilities: characteristics, diagnosis, and assessment. Res Autism Spectrum Disord. 2011;5:1459–64. https://doi.org/10.1016/j.rasd.2011.02.006. 15. Barker D. Tooth wear as a result of pica. Br Dent J. 2005;199:271–3. 16. Woywodt A, Kiss A. Geophagia: the history of earth eating. J R Soc Med. 2002;95:143–6. 17. Barton JC, Barton JC, Bertoli LF. Pica for uncooked Basmati rice in two women with iron deficiency and a review of Ryzophagia. Case Rep Med. 2016;2016:8159302. https://doi. org/10.1155/2016/8159302. 18. Voigt CC, Capps KA, Dechmann DKN, Michener RH, Kunz TH.  Nutrition or detoxification: why bats visit mineral licks of the Amazonian rainforest. PLoS ONE. 2008;3(4):e2011. https://doi.org/10.1371/journal.pone.0002011. 19. Horner RD, Lackey CJ, Kolasa K, Warren K. Pica practices of pregnant women. J Am Diet Assoc. 1991;91:34–8. 20. Crosby WH. Pica. JAMA. 1976;235:27–65. 21. Mengel CE, Carter WA, Horton ES. Geophagia with iron deficiency anemia and hypokalemia. Arch Intern Med. 1964;114:471–4. 22. Olynyk F, Sharpe DH. Mercury poisoning and paper pica. N Engl J Med. 1982;306:1056–7. 23. Allen JD, Woodruff J.  Starch gastrolith: report of a case of obstruction. N Engl J Med. 1963;268:776–8. https://doi.org/10.1056/NEJM196304042681408. 24. Advani S, Kochhar G, Chachra S, Dhawan P. Eating everything except food (Pica): a rare case report and review. J Int Soc Prev Community Dent. 2014;4(1):1–4. 25. Halland M, Pandolfino J, Barba E. Diagnosis and treatment of rumination syndrome. Clin Gastroenterol Hepatol. 2018;16:1549–55. 26. Papadopoulos V, Mimidis K. The rumination syndrome in adults: a review of the pathophysiology, diagnosis and treatment. J Postgrad Med. 2007;53:203–6. 27. Murray HB, Juarascio AS, Di Lorenzo C, Drossman DA, Thomas JJ. Diagnosis and treatment of rumination syndrome: a critical review. Am J Gastroenterol. 2019;114:562–78. 28. Pauwels A, Broers G, Van Houtte B, Rommel N, Vanuytsel T, Tack J. A randomized double-­ blind, placebo-controlled, cross-over study using Baclofen in the treatment of rumination syndrome. Am J Gastroenterol. 2018;113:97–104. 29. Monagas J, Ritwik P, Kolomensky A, Acosta J, Kay D, Clendaniel L, Hyman PE. Rumination syndrome and dental erosions in children. J Pediatr Gastroenterol Nutr. 2017;64:930–2. 30. Weakley MM, Petti TA, Karwisch G. Case study: chewing gum treatment of rumination in an adolescent with an eating disorder. J Am Acad Child Adolesc Psychiatry. 1997;36(8):1124–7.

64

A. Milosevic and F. Amir-Rad

31. Rhine D, Tarbox J. Chewing gum as a treatment for rumination in a child with autism. J Appl Behav Anal. 2009;42(2):381–5. https://doi.org/10.1901/jaba.2009.42-­381. 32. Levine DF, Wingate DL, Pfeffer JM, Butcher P. Habitual rumination: a benign disorder. Br Med J. 1983;287(6387):255–6. https://doi.org/10.1136/bmj.287.6387.255. 33. Burtner AP, Poppell TD. Dental sequelae of chronic rumination: report of cases. Spec Care Dentist. 1987;7(4):154–6. https://doi.org/10.1111/j.1754-­4505.1987.tb00631.x. 34. Gilmour AG, Beckett HA. The voluntary reflux phenomenon. Br Dent J. 1993;175:368–72. https://doi.org/10.1038/sj.bdj.4808327. 35. Schlueter N, Amaechi BT, Bartlett B, Buzalaf MAR, Carvalho TS, Ganss C, et al. Terminology of erosive tooth wear: consensus report of a workshop organized by the ORCA and the cariology research group of the IADR. Caries Res. 2019:1–5. https://doi.org/10.1159/000503308. 36. Kessler RC, Berglund PA, Chiu WT, et  al. The prevalence and correlates of binge eating disorder in the World Health Organization World Mental Health Surveys. Biol Psychiatry. 2013;73:904–14. https://doi.org/10.1016/j.biopsych.2012.11.020. 37. Hoek HW, Van Hoeken D. Review of the prevalence and incidence of eating disorders. Int J Eat Disord. 2003;34:383–96. https://doi.org/10.1002/eat.10222. 38. Rosten A, Newton T. The impact of bulimia nervosa on oral health: a review of the literature. Br Dent J. 2017;223(7):533–9. https://doi.org/10.1038/sj.bdj.2017.837. 39. Coelho GM, Gomes AI, Ribeiro BG, Soares EA. Prevention of eating disorders in female athletes. J Sports Med. 2014;5:105–13. https://doi.org/10.2147/OAJSM.S36528. 40. Baum A.  Eating disorders in the male athlete. Sports Med. 2006;36(1):1–6. https://doi. org/10.2165/00007256-­200636010-­00001. 41. Joy E, Kussman A, Nattiv A. 2016 update on eating disorders in athletes: a comprehensive narrative review with a focus on clinical assessment and management. Br J Sports Med. 2016;50(3):154–62. https://doi.org/10.1136/bjsports-­2015-­095735. 42. Franko DL, Keel PK. Suicidality in eating disorders: occurrence, correlates, and clinical implications. Clin Psychol Rev. 2006;26(6):769–82. https://doi.org/10.1016/j.cpr.2006.04.001. 43. Peebles R, Wilson JL, Lock JD.  Self-injury in adolescents with eating disorders: correlates and provider bias. J Adolesc Health. 2011;48(3):310–3. https://doi.org/10.1016/j. jadohealth.2010.06.017. 44. Golden NH, Attia E. Psychopharmacology of eating disorders in children and adolescents. Pediatr Clin North Am. 2011;58(1):121–38. https://doi.org/10.1016/j.pcl.2010.11.001. 45. Arcelus J, Mitchell AJ, Wales J, Nielsen S.  Mortality rates in patients with anorexia nervosa and other eating disorders. a meta-analysis of 36 studies. Arch Gen Psychiatry. 2011;68(7):724–31. https://doi.org/10.1001/archgenpsychiatry.2011.74. 46. Franko DL, Keshaviah A, Eddy KT, Krishna M, Davis MC, Keel PK, et  al. A longitudinal investigation of mortality in anorexia nervosa and bulimia nervosa. Am J Psychiatry. 2013;170(8):917–25. 47. Dalle Grave R, Calugi S, Marchesini G. Self-induced vomiting in eating disorders: associated features and treatment outcome. Behav Res Ther. 2009;47(8):680–4. 48. Tozzi F, Thornton LM, Mitchell J, Fichter MM, Klump KL, Lilenfeld LR, et  al. Features associated with laxative abuse in individuals with eating disorders. Psychosom Med. 2006;68(3):470–7. 49. Bryant-Waugh R, Turner H, East P, Gamble C, Mehta R. Misuse of laxatives among adult outpatients with eating disorders: prevalence and profiles. Int J Eat Disord. 2006;39(5):404–9. 50. Katzman D.  Medical complications in adolescents with anorexia nervosa: a review of the literature. Int J Eat Disord. 2005;37:s22–59. 51. Galetta F, Franzoni F, Prattichizzo F, Rolla M, Santoro G, Pentimone F.  Heart rate variability and left ventricular diastolic function in anorexia nervosa. J Adolesc Health. 2003;32(6):416–21. 52. Misra M, Aggarwal A, Miller KK, Almazan C, Worley M, Soyka LA, et al. Effects of anorexia nervosa on clinical, hematologic, biochemical, and bone density parameters in community-­ dwelling adolescent girls. Pediatrics. 2004;114(6):1574–83. 53. Walsh JME, Wheat ME, Freund K. Detection, evaluation, and treatment of eating disorders. J Gen Intern Med. 2000;15:577–90.

5  Feeding and Eating Disorders: Behaviours That Adversely Impact Oral Health

65

54. Forney KJ, Buchman-Schmitt JM, Keel PK, Frank GK. The medical complications associated with purging. Int J Eat Disord. 2016;49(3):249–59. 55. Meczekalski B, Podfigurna-Stop A, Katulski K. Long-term consequences of anorexia nervosa. Maturitas. 2013;75(3):215–20. 56. Zipfel S, Sammet I, Rapps N, Herzog W, Herpertz S, Martens U.  Gastrointestinal disturbances in eating disorders: clinical and neurobiological aspects. Auton Neurosci. 2006;129(1-2):99–106. https://doi.org/10.1016/j.autneu.2006.07.023. 57. Price C, Schmidt MA, Adam EJ, Lacey H. Parotid gland enlargement in eating disorders: an insensitive sign? Eat Weight Disord. 2008;13(4):e79–83. 58. Repesse X, Bodson L, Au SM, Charron C, Vieillard-Baron A. Gastric dilatation and circulatory collapse due to eating disorder. Am J Emerg Med. 2013;31(3):e633–4. 59. Mehanna HM, Moledina J, Travis J. Refeeding syndrome: what it is, and how to prevent and treat it. BMJ. 2008;336(7659):1495–8. https://doi.org/10.1136/bmj.a301. 60. Harrington B, Jimmerson M. Initial evaluation, diagnosis, and treatment of anorexia nervosa and bulimia nervosa. Am Fam Physician. 2015;91(1):46–52. 61. Mascolo M, Trent S, Colwell C, Mehler PS. What the emergency department needs to know when caring for your patients with eating disorders. Int J Eat Disord. 2012;45(8):977–81. https://doi.org/10.1002/eat.22035. 62. Harrop EN, Marlatt GA. The comorbidity of substance use disorders and eating disorders in women: prevalence, etiology, and treatment. Addict Behav. 2010;35(5):392–8. https://doi. org/10.1016/j.addbeh.2009.12.016. 63. Garrido-Martínez P, Domínguez-Gordillo A, Cerero-Lapiedra R, Burgueño-García M, Martínez-Ramírez MJ, Gómez-Candela C, et al. Oral and dental health status in patients with eating disorders in Madrid, Spain. Med Oral Patol Oral Cir Bucal. 2019;24(5):e595–602. 64. Krug I, Treasure J, Anderluh M, Bellodi L, Cellini E, Di Bernardo M.  Present and lifetime comorbidity of tobacco, alcohol and drug use in eating disorders: a European multicenter study. Drug Alcohol Depend. 2008;97(1-2):169–79. https://doi.org/10.1016/j. drugalcdep.2008.04.015. 65. Piper ME, Smith SS, Schlam TR, Fleming MF, Bittrich AA, Brown JL. Psychiatric disorders in smokers seeking treatment for tobacco dependence: relations with tobacco dependence and cessation. J Consult Clin Psychol. 2010;78(1):13–23. https://doi.org/10.1037/a0018065. 66. Cooper R.  Could your patient have an eating disorder? Nurs Womens Health. 2013;17(4):317–24. https://doi.org/10.1111/1751-­486X.12050. 67. Misra M, Klibanski A.  Neuroendocrine consequences of anorexia nervosa in adolescents. Endocr Dev. 2010;17:197–214. https://doi.org/10.1159/000262540. 68. Russell G.  Bulimia nervosa: an ominous variant of anorexia nervosa. Psychol Med. 1979;9(3):429–48. 69. Glorio R, Allevato M, De Pablo A, Abbruzzese M, Carmona L, Savarin M, et al. Prevalence of cutaneous manifestations in 200 patients with eating disorders. Int J Dermatol. 2000;39(5):348–53. 70. Weinstein HD, Halabis JA.  Subconjunctival hemorrhage in bulimia. J Am Optom Assoc. 1986;57(5):366–7. 71. Baiano M, Salvo P, Righetti P, Cereser L, Baldissera E, Camponogara I, et  al. Exploring health-related quality of life in eating disorders by a cross-sectional study and a comprehensive review. BMC Psychiatry. 2014;14(165) https://doi.org/10.1186/1471-­244X-­14-­165. 72. Davies M, Brody D, deGruy FV, Spitzer RL, Kroenke K, Linzer M, et al. Health-related quality of life in primary care patients with mental disorders. Results from the PRIME-MD 1000 Study. JAMA. 1995;274:1511–7. 73. Winkler LA, Christiansen E, Lichtenstein MB, Hansen NB, Bilenberg N, Støving RK. Quality of life in eating disorders: a meta-analysis. Psychiatry Res. 2014;219(1):1–9. 74. Ágh T, Kovács G, Supina D, Pawaskar M, Herman BK, Vokó Z, et al. A systematic review of the health-related quality of life and economic burdens of anorexia nervosa, bulimia nervosa, and binge eating disorder. Eat Weight Disord. 2016;21(3):353–64.

66

A. Milosevic and F. Amir-Rad

75. González‐Pinto A, Inmaculada F, Cristina R, de Corres Blanca F, Sonsoles E, Fernando R, et al. Purging behaviors and comorbidity as predictive factors of quality of life in anorexia nervosa. Int J Eat Disord. 2004;36(4):445–50. 76. Latner JD, Vallance JK, Buckett G. Health-related quality of life in women with eating disorders: association with subjective and objective binge eating. J Clin Psychol Med Settings. 2008;15(2):148–53. 77. Padierna A, Quintana JM, Arostegui I, Gonzalez N, Horcajo MJ. The healthrelated quality of life in eating disorders. Qual Life Res. 2000;9:667–74. 78. Grenon R, Tasca GA, Cwinn E, Coyle D, Sumner A, Gick M, et al. Depressive symptoms are associated with medication use and lower health-related quality of life in overweight women with binge eating disorder. Womens Health Issues. 2010;20(6):435–40. 79. de Zwaan M, Lancaster KL, Mitchell JE, Howell LM, Monson N, Roerig JL, et  al. Healthrelated quality of life in morbidly obese patients: effect of gastric bypass surgery. Obes Surg. 2002;12(6):773–180. 80. de Zwaan M, Mitchell JE, Howell LM, Monson N, Swan-Kremeier L, Roerig JL, et al. Two measures of health-related quality of life in morbid obesity. Obes Res. 2002;10(11):1143–51. 81. Hsu LK, Mulliken B, McDonagh B, Krupa Das S, Rand W, Fairburn CG, et al. Binge eating disorder in extreme obesity. Int J Obes Relat Metab Disord. 2002;26(10):1398–403. 82. Masheb RM, Grilo CM. Quality of life in patients with binge eating disorder. Eat Weight Disord. 2004;9(3):194–9. 83. Rieger E, Wilfley DE, Stein RI, Marino V, Crow SJ. A comparison of quality of life in obese individuals with and without binge eating disorder. Int J Eat Disord. 2005;37:234–40. 84. Hart LM, Gordon AR, Sarda V, Calzo JP, Sonneville KR, Samnaliev M, et al. The association of disordered eating with health-related quality of life in U.S. young adults and effect modification by gender. Qual Life Res. 2020; [Epub ahead of print] 85. Areemit RS, Katzman DK, Pinhas L, Kaufman ME. The experience of siblings of adolescents with eating disorders. J Adolesc Health. 2010;46(6):569–76. 86. de la Rie SM, van Furth EF, De Koning A, Noordenbos G, Donker MC. The quality of life of family caregivers of eating disorder patients. Eat Disord. 2005;13(4):345–51. 87. Gonzalez N, Bilbao A, Padierna A, Martín J, Orive M, Quintana JM. Validity and reliability of the Spanish version of the involvement evaluation questionnaire among caregivers of patients with eating disorders. Psychiatry Res. 2012;200(2-3):896–903. 88. Martın J, Padierna A, Aguirre U, Quintana JM, Haya CL, Muñoz P. Quality of life among caregivers of patients with eating disorders. Qual Life Res. 2011;20(9):1359–69. 89. de la Rie SM, Noordenbos G, van Furth EF. Quality of life and eating disorders. Qual Life Res. 2005;14(6):1511–22. 90. Pohjolainen V, Koponen S, Räsänen P, Roine RP, Sintonen H, Karlsson H. Long-term health-­ related quality of life in eating disorders. Qual Life Res. 2016;25:2341–6. 91. DeJong H, Oldershaw A, Sternheim L, Samarawickrema N, Kenyon MD, Broadbent H, Lavender A, Startup H, Treasure J, Schmidt U.  Quality of life in anorexia nervosa, bulimia nervosa and eating disorder not-otherwise-specified. J Eat Disord. 2013 Nov;26(1):43. https://doi.org/10.1186/2050-­2974-­1-­43. 92. Hellstrom I. Oral complications in anorexia nervosa. Scand J Dent Res. 1977;85:71–86. 93. Hurst PS, Lacey JH, Crisp AH. Teeth, vomiting and diet: a study of the dental characteristics of seventeen anorexia nervosa patients. Postgrad Med J. 1977;53(620):298–305. https://doi. org/10.1136/pgmj.53.620.298. 94. Lo Russo L, Campisi G, di Fede O, di Liberto C, Panzarella V, Lo ML. Oral manifestations of eating disorders: a critical review. Oral Dis. 2008;14(6):479–84. https://doi.org/10.1111/j.1601-­ 0825.2007.01422.x. 95. Little JW. Eating disorders: dental implications. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2002;93(2):138–43. https://doi.org/10.1067/moe.2002.116598. 96. Romanos GE, Javed F, Romanos EB, Williams RC. Oro-facial manifestations in patients with eating disorders. Appetite. 2012;59(2):499–504. https://doi.org/10.1016/j.appet.2012.06.016.

5  Feeding and Eating Disorders: Behaviours That Adversely Impact Oral Health

67

97. Otsu M, Hamura A, Miyauchi M, Okada T, Karibe H, Ishii T, et al. Efficiency of a mouth guard to prevent a toothache (cold-water pain) in a patient with eating disorder accompanied by self-induced vomiting. Jpn J Psychosom Med. 2010;50(2):139–45. 98. Emodi-Perlman A, Yoffe T, Rosenberg N, Eli I, Alter Z, Winocur E. Prevalence of psychologic, dental, and temporomandibular signs and symptoms among chronic eating disorders patients, a comparative control study. J Orofac Pain. 2008;22(3):201–8. 99. Ganss C, Lussi A, Schlueter N. Dental erosion as oral disease. Insights in etiological factors and pathomechanisms, and current strategies for prevention and therapy. Am J Dent. 2012;25(6):351–64. 100. Lussi A, Hellwig E, Zero D, Jaeggi T. Erosive tooth wear: diagnosis, risk factors and prevention. Am J Dent. 2006;19(6):319–25. 101. Simmons MS, Grayden SK, Mitchell JE. The need for psychiatric-dental liaison in the treatment of bulimia. Am J Psychiatry. 1986;143(6):783–4. https://doi.org/10.1176/ajp.143.6.783. 102. Roberts MW, Li S-H.  Oral findings in anorexia nervosa and bulimia nervosa: a study of 47 cases. J Am Dent Assoc. 1987;115(3):407–10. https://doi.org/10.14219/jada. archive.1987.0262. 103. Jones RRH, Cleaton-Jones P. Depth and area of dental erosions and dental caries in bulimic women. J Dent Res. 1989;68(8):1275–8. 104. Milosevic A, Slade PD.  The orodental status of anorexics and bulimics. Br Dent J. 1989;167(2):66–70. 105. Altshuler BA, Dechow PC, Waller DA, Hardy BW. An investigation of the oral pathologies occurring in bulimia nervosa. Int J Eating Disord. 1990;9(2):191–9. 106. Philipp E, Willershausen-Zönnchen B, Hamm G, Pirke K-M. Oral and dental characteristics in bulimic and anorectic patients. Int J Eating Disord. 1991;10(4):423–31. 107. Touyz SW, Liew VP, Tseng P, Frisken K, Williams H, Beumont PJV. Oral and dental complications in dieting disorders. Int J Eating Disord. 1993;14(3):341–8. 108. Robb ND, Smith BGN, Geidrys-Leeper E. The distribution of erosion in the dentitions of patients with eating disorders. Br Dent J. 1995;178:171–5. 109. Rytömaa I, Järvinen V, Kanerva R, Heinonen OP. Bulimia and tooth erosion. Acta Odontol Scand. 1998;56:36–40. 110. Öhrn R, Enzell K, Angmar-Månsson B. Oral status of 81 subjects with eating disorders. Eur J Oral Sci. 1999;107:157–63. 111. Montecchi PP, Custureri V, Polimeni A, Cordaro M, Costa L, Marinucci S, et  al. Oral manifestations in a group of young patients with anorexia nervosa. Eating Weight Disord. 2003;8(2):164–7. 112. Dynesen AW, Bardow A, Petersson B, Nielsen LR, Nauntofte B.  Salivary changes and dental erosion in bulimia nervosa. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2008;106(5):696–707. 113. Otsu M, Hamura A, Ishikawa Y, Karibe H, Ichijyo T, Yoshinaga Y. Factors affecting the dental erosion severity of patients with eating disorders. Biopsychosoc Med. 2014;8(25) https://doi. org/10.1186/1751-­0759-­8-­25. 114. Uhlen M, Tveit AB, Stenhagen KR, Mulic A.  Self-induced vomiting and dental erosion-a clinical study. BMC Oral Health. 2014;14(1):92–8. 115. Johansson A, Norring C, Unell L, Johansson A. Eating disorders and oral health: a matched case–control study. Eur J Oral Sci. 2012;120(1):61–8. 116. Hermont AP, Pordeus IA, Paiva SM, Abreu MH, Auad SM. Eating disorder risk behavior and dental implications among adolescents. Int J Eat Disord. 2013;46(7):677–83. 117. Jugale PV, Pramila M, Murthy AK, Rangath S.  Oral manifestations of suspected eating disorders among women of 20–25 years in Bangalore City. India. J Health Popul Nutr. 2014;32(1):46–50. 118. Lourenço M, Azevedo A, Brandão I, Gomes PS. Orofacial manifestations in outpatients with anorexia nervosa and bulimia nervosa focusing on vomiting behavior. Clin Oral Investig. 2018 Jun;22(5):1915–22. https://doi.org/10.1007/s00784-­017-­2284-­y.

68

A. Milosevic and F. Amir-Rad

119. Hermont AP, Oliveira PAD, Martins CC, Paiva SM, Pordeus IA, Auad SM. Tooth erosion and eating disorders: a systematic review and meta-analysis. PLoS One. 2014;9(11):e111123. https://doi.org/10.1371/journal.pone.0111123. 120. Kisely S, Baghaie H, Lalloo R, Johnson NW. Association between poor oral health and eating disorders: systematic review and meta-analysis. Br J Psychiatry. 2015;207(4):299–305. https://doi.org/10.1192/bjp.bp.114.156323. 121. Meurman JH, ten Cate JM. Pathogenesis and modifying factors of dental erosion. Eur J Oral Sci. 1996;104(2):199–206. https://doi.org/10.1111/j.1600-­0722.1996.tb00068.x. 122. Hamasha AA, Zawaideh FI, Al-Hadithy RT.  Risk indicators associated with dental erosion among Jordanian school children aged 12–14 years of age. Int J Paediatr Dent. 2014;24(1):56–68. https://doi.org/10.1111/ipd.12026. 123. Milosevic A, Brodie DA, Slade PD.  Dental erosion, oral hygiene, and nutrition in eating disorders. Int J Eat Disord. 1997;21(2):195–9. 124. Crow SJ, Peterson CB, Swanson SA, Raymond NC, Specker S, Eckert ED, et al. Increased mortality in bulimia nervosa and other eating disorders. Am J Psychiatry. 2009;166(12):1342–6. https://doi.org/10.1176/appi.ajp.2009.09020247. 125. Brandt LMT, Fernandes LHF, Aragão AS, Aguiar YPC, Auad SM, de Castro RD, et  al. Relationship between risk behavior for eating disorders and dental caries and dental erosion. Sci World J. 2017;1656417 https://doi.org/10.1155/2017/1656417. 126. Terry-Short LA, Glynn Qwens R, Slade PD, Dewey ME. Positive and negative perfectionism. Person Individ Diff. 1995;18(5):663–8. https://doi.org/10.1016/0191-­8869(94)00192-­U. 127. Wolcott RB, Yager J, Gordon G.  Dental sequelae to the binge-purge syndrome (bulimia): report of cases. J Am Dent Assoc. 1984;109:723–5. 128. Bretz WA, Krahn DD, Drewnowski A, Loesehe WJ. Salivary levels of putative cariogenic organisms in patients with eating disorders. Oral Microbiol Immunol. 1989;4(4):230–2. https://doi.org/10.1111/j.1399-­302x.1989.tb00258.x. 129. Coleman H, Altini M, Naylor S, Richards A. Sialadenosis, a presenting sign in bulimia. Head Neck Pathol. 1998;20(8):758–62. 130. Mandel L, Abai S.  Diagnosing bulimia nervosa with parotid gland swelling. J Am Dent Assoc. 2004;135(5):613–6. 131. Park KK, Tung RC, de Luzuiaga A. Painful parotid hypertrophy with bulimia: a report of medical management. J Drugs Dermatol. 2009;8(6):577–9. 132. Lifante-Oliva C, Lopez-Jornet P, Camacho-Alonso F, Esteve-Salinas J.  Study of oral changes in patients with eating disorders. Int J Dent Hygiene. 2008;6(2):119–22. https://doi. org/10.1111/j.1601-­5037.2008.00296.x. 133. Johansson A-K, Norring C, Unell L, Johansson A. Eating disorders and biochemical composition of saliva: a retrospective matched case–control study. Eur J Oral Sci. 2015;123(3):158–64. https://doi.org/10.1111/eos.12179. 134. Schlueter N, Ganss C, Pötschke S, Klimek J, Hannig C. Enzyme activities in the oral fluids of patients suffering from bulimia: a controlled clinical trial. Caries Res. 2012;46(2):130–9. https://doi.org/10.1159/000337105. 135. Lussi A, von Salis-Marincek M, Ganss C, Hellwig E, Cheaib Z, Jaeggi T.  Clinical study monitoring the pH on tooth surfaces in patients with and without erosion. Caries Res. 2012;46(6):507–12. https://doi.org/10.1159/000339783. 136. Keith O, Flint S.  Lingual abscess in a patient with anorexia nervosa. Br Dent J. 1989;167(2):71–2. https://doi.org/10.1038/sj.bdj.4806916. 137. Imai T, Michizawa M.  Necrotizing sialometaplasia in a patient with an eating disorder: Palatal ulcer accompanied by dental erosion due to binge-purging. J Oral Maxillofac Surg. 2013;71(5):879–85. 138. Janner SF, Suter VG, Altermatt HJ, Reichart PA, Bornstein MM. Bilateral necrotizing sialometaplasia of the hard palate in a patient with bulimia: a case report and review of the literature. Quintessence Int. 2014;45(5):431–7. https://doi.org/10.3290/j.qi.a31543.

5  Feeding and Eating Disorders: Behaviours That Adversely Impact Oral Health

69

139. Solomon LW, Merzianu M, Sullivan M, Rigual NR. Necrotizing sialometaplasia associated with bulimia: case report and literature review. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2007;103(2):e39–42. https://doi.org/10.1016/j.tripleo.2006.08.005. 140. Johansson AK, Johansson A, Unell L, Norring C, Carlsson GE. Eating disorders and signs and symptoms of temporomandibular disorders, a matched case-control study. Swed Dent J. 2010;34(3):139–47. 141. Willumsen T, Graugaard PK. Dental fear, regularity of dental attendance and subjective evaluation of dental erosion in women with eating disorders. Eur J Oral Sci. 2005;113(4):297–302. 142. Sirin Y, Firat D, Husseinova-Sen S. Assessment of dental fear and anxiety levels in eating disorder patients undergoing minor oral surgery. J Oral Maxillofac Surg. 2011;69:2078–85. 143. Conviser JH, Fisher SD, Mitchell KB. Oral care behavior after purging in a sample of women with bulimia nervosa. J Am Dent Assoc. 2014;145(4):352–4. https://doi.org/10.14219/ jada.2014.5. 144. Kidd EA, Smith BGN. Toothwear histories: a sensitive issue. Dent Update. 1993;20(4):174–8. 145. National Institute for Health and Care Excellence. Eating disorders: recognition and treatment. Nice guideline published 23 May 2017. Retrieved from: www.nice.org.UK/guidance/ng69

6

Physiology of Erosive Tooth Wear and Relationship with Dentine Hypersensitivity Saoirse O’Toole and Owen Addison

6.1

Introduction

Erosive tooth wear is defined as the chemo-mechanical removal of dental tissue in the absence of bacteria [1]. Although the term ‘tooth wear’ is commonly used in the United Kingdom, the term erosive tooth wear is increasing globally to recognise that, clinically severe wear rarely occurs without an underlying acid component acting alongside mechanical removal. Dietary acids and gastric acids are the most common underlying acid aetiologies in erosive tooth wear. Although we all consume dietary acids, it is when we consume them at an increased frequency or for prolonged durations that they can contribute to erosive tooth wear [2]. Although gastric acid erosion is less common, gastric acids are stronger acids (producing more protons in solution) and have been shown to bypass the protective salivary pellicle at a faster rate [3]. In common with extrinsic dietary acid exposures, it is the timing, periodicity and frequency of intraoral acid exposures which influence the clinical pattern and progression of tooth substrate loss. Dentine hypersensitivity is characterised by short, sharp, transient pain in response to stimuli which cannot be attributed to any other form of pathology [4]. The hydrodynamic theory originally described by Gysi in the 1900’s describes this pain to be a result from fluid movement within dentine tubules. Odontoblast bodies are located within the pulpal aspect of the dentine with the odontoblast processes extending a few microns into the tubule. The rest of the tubule is filled with fluid. Stimulating this fluid, either through thermal, tactile or osmotic stimuli will cause fluid movement. When this movement is large enough it will stimulate the A delta fibres in the pulp periphery, just below the odontoblast cell bodies, triggering sharp pain. S. O’Toole (*) · O. Addison Centre for Clinical, Oral and Translational Sciences, Faculty of Dental, Oral and Craniofacial Sciences, King’s College London, London, UK e-mail: [email protected]; [email protected] © Springer Nature Switzerland AG 2022 A. Eder, M. Faigenblum (eds.), Tooth Wear, BDJ Clinician’s Guides, https://doi.org/10.1007/978-3-030-86110-0_6

71

72

S. O’Toole and O. Addison

Both erosive tooth wear and dentine hypersensitivity are increasing in prevalence, particularly amongst the younger populations [5, 6]. This chapter will cover the early wear process and give reasons why acid exposure or harsh mechanical wear can possibly lead to dentine hypersensitivity.

6.2

 Recap on Enamel Physiology with Respect A to Tooth Wear

Enamel is one of the hardest structures in the human body. It has roughly 96% mineral content in the form of substituted calcium hydroxyapatite, 3% water and 1% organic tissue. Hydroxyapatite crystals are arranged in key-hole shaped prism structures which run perpendicular to the outermost layer of enamel. On tooth eruption, the outside layer of enamel, is a relatively disorganised structure, containing no prisms and hence is called the ‘aprismatic layer’ which is up to 100 μm deep. It has the highest mineral content, containing fluoride and phosphate in the form of fluorohydroxyapatite [7]. This layer has been shown to offer the greatest protection against both acid and mechanical challenges. The enamel prisms are separated by the inter-prismatic layer. The inter-prismatic layer is composed of less organised hydroxyapatite, but with a relatively high proportion of proteins and organic tissue. Due to its high mineral content, enamel is very strong against mechanical challenges but weak against acidic challenges.

6.3

A Recap on Dentine Physiology with Respect to Wear

Dentine is a permeable structure composed of 75% mineral, 20% organic material and 5% water. Each odontoblast forms one tubule, laying down mineral tissue around the cell processes and body. The diameter of tubules varies between 2–4 μm with tubule density increasing towards the pulp [8]. Closest to enamel is the mantle dentine, which is roughly 15–30 μm thick. Mantle dentine, similar to the aprismatic layer in enamel, is disorganised and only has a few thin, curved tubules. The bulk of dentine consists of intertubular dentine, a type I collagen-rich structure. Each collagen fibril is 100–120 nm thick in diameter. This collagen network is moisture rich and elastic resulting in reduced hardness and higher susceptibility to wear, such as abrasion. Dentine apatite crystals are needle-like structures, 3–4  nm thick and located either along the surface of the collagen fibrils or filling the empty intra-­ collagen spaces [8]. Peritubular dentin is formed within the lumen of the tubules. It is formed by a network of proteins and apatite crystals with no collagen fibrils. Peritubular dentin is highly mineralised making it more susceptible to an acid challenge. Secondary dentine is laid down slowly within the pulp chamber after the tooth has erupted and often contains an irregular distribution of dentine tubules. ‘Tertiary’, ‘reparative’, or ‘reactionary’ dentine laid down in response to irritation, such as dental caries often contains no dentine tubules [8].

6  Physiology of Erosive Tooth Wear and Relationship with Dentine Hypersensitivity

73

In order for dentine hypersensitivity to occur, dentine needs to be exposed, the tubules need to be patent and, more than likely, widened [9]. Erosive tooth wear can expose the dentine through removing enamel and the protective smear layer. Once the mineralised peritubular dentine is exposed, it can then widen the tubules. These are discussed in the following sections below.

6.4

 efence Systems Against Dentine Hypersensitivity D and How Erosive Tooth Wear Overcomes Them

6.4.1 F  irst Layer of Defence Against Dentine Hypersensitivity: Enamel Enamel is the first line of defence against erosive tooth wear. In the absence of acid challenges, enamel is the hardest structure in the body and can withstand a good degree of mechanical attrition and abrasion. When teeth are exposed to an acidic environment, minerals are released from the surface causing softening of the outermost layer between 0.2 and 2 μm thick [10, 11]. When acid encounters a natural enamel surface, there is initial breakdown of the interface between the prism and interprismatic layer widening the prism [12]. Thereafter, the prism cores are richer in carbonate, making them more susceptible to erosion. Liquid can move through enamel prisms of the teeth causing subsurface softening [13]. In the absence of further erosive challenges or mechanical removal, there is possibility for minerals to form new ionic bonds in the acid softened enamel [14]. However, complete remineralisation of enamel after a severe acid challenge is very difficult to achieve in  vivo and more recent research has suggested that proteins in saliva can interfere with remineralisation [15]. In one clinical study whereby teeth scheduled for extraction were acid etched for 2 min with 50% phosphoric acid, microscopic evidence of the etching was still present when the teeth were extracted 90 days later [16]. Enamel samples eroded with dietary acid challenges have also been found to not regain their original hardness after being left in the mouth undisturbed for 7 days [17]. As the acid challenge continues, layers of enamel become softened and are further eroded, resulting in bulk irreversible enamel loss. When softened, enamel is particularly susceptible to mechanical forces [10]. Toothbrushing, in the absence of an acid challenge, causes a negligible amount of enamel tooth structure loss when a low or medium abrasivity toothpaste is used [18]. However, in the presence of an acid challenge, minimal abrasive or mechanical wear can remove any softened enamel. Any attritive or abrasive wear will occur at a much faster rate in the presence of an acid, hence the reason why severe tooth wear rarely presents with a single aetiology. The maximum bite forces generated by humans are roughly 700 N [19], roughly equivalent to the force on the ground generated by a 70  kg person. The typical forces seen when chewing or swallowing are surprisingly high at roughly 36–41% of the maximum force (forces of between 250–290 N were observed) [20]. Bruxism forces are estimated to be in the range of 30% of maximum (approximately 220 N) [21]. Enamel is remarkably well equipped to deal with these forces with many

74

S. O’Toole and O. Addison

laboratory studies finding negligible enamel wear in the absence of an acid challenge. However, aggressive wear can occur on acid softened enamel using relatively low forces [22]. A Quick Note on Abfraction

Abfraction has been defined as tooth wear along the cemento-enamel junction (CEJ) caused by eccentric loading of the tooth. The CEJ is a weak point on the tooth. The enamel is at its thinnest and the junction with cementum is a known mechanical weak point as observed by multiple studies in finite element analysis studies. It was a commonly held theory that repeated flexure of the tooth led to microfractures of the dental tissues causing non-carious cervical lesions. However, there is limited evidence to suggest that these lesions have an occlusal aetiology. They rarely occur on the lingual surfaces of teeth and are not correlated with those who have eccentric contacts or high levels of bruxism [23]. These lesions are easily replicated in the laboratory through combinations of abrasion and erosion, whereas it is almost impossible to replicate them using physiological levels of eccentric loading or occlusal contacts. This has led to the international consensus that ‘abfraction’ is not an aetiological factor in erosive tooth wear [24]. Restoring these lesions is notoriously difficult and it is highly likely that occlusal factors play a role in the longevity of these restorations. However, occlusal factors are unlikely to play a role in the initiation of tooth wear lesions although they may exacerbate them. Instead, clinical examinations should focus on identifying erosive and abrasive aetiologies. Once enamel is worn away, dentine is exposed and the risk for dentine hypersensitivity increases. However, exposure of dentine does not always lead to dentine hypersensitivity. This is because fluid movement within the tubules is limited by both the smear layer on the surface of the dentine and secondary/tertiary dentine on the pulpal border of the dentine. Both are affected by erosive tooth wear and are discussed in the following two sections.

6.4.2 S  econd Line of Defence Against Dentine Hypersensitivity: The Smear Layer If the hydrodynamic theory of dentine hypersensitivity is correct, whereby pain is caused by rapid changes in fluid within the tubule, blocking or sealing the tubule should prevent pain. The naturally occurring smear layer, formed as a consequence of intraoral exposure, is a thin ‘loose’ layer of organic collagen and proteins coming from saliva and dentine particles which form an adherent matrix for mineralised tissue [25]. This smear layer is excellent at occluding dentinal tubules and limiting dentine hypersensitivity [26]. The smear layer is remarkably stable under normal oral conditions and several studies have shown that the smear layer is a better sealant than adhesive resins under normal oral conditions [27]. It is not removed by toothbrushing

6  Physiology of Erosive Tooth Wear and Relationship with Dentine Hypersensitivity

75

with a normal force and replenishes in a non-aggressive environment [28]. However, the smear layer is highly susceptible to acid challenges [29]. In day-­to-­day clinical dentistry, we are used to removing the smear layer with acid for our bonding procedures. Laboratory studies have shown that dietary acid challenges can also dissolve this protective layer [30]. One clinical study observed that consuming a dietary acid within the previous hour was related to increased clinical dentine hypersensitivity on examination [31]. Once the smear layer is removed, the mineralised peri-tubular dentine is exposed. This means that continued acid challenges will widen the dentinal tubules, making the tubules more difficult to occlude [32]. The habit of consuming dietary acids over a long period of time has been associated with increased levels of dentine hypersensitivity compared to those who consumed dietary acids more frequently but over a short period of time [33]. Aggressive mechanical challenges have also been shown to remove the smear layer. Toothbrushing with a force of 400  g (normal brushing force is 100–300 g), has been shown to increase the number of patent dentine tubules [34]. In contrast to enamel, attritional forces alone have the capacity to remove exposed dentine. This again is worse on acid softened dentine [35]. To date, there have been no studies demonstrating that attritional forces can remove the smear layer, however this may also be a possibility. A Quick Note on Saliva

The relationship between saliva (Chap. 4), erosive tooth wear and dentine hypersensitivity is not straightforward. The salivary pellicle is a protein layer that forms rapidly and spontaneously through protein adsorption to the tooth surface. Whilst it is essential for the subsequent colonisation of the tooth surface by bacteria to form a biofilm, it can also be considered to provide a protective barrier to the dental surface. The thickness and protein content of this pellicle has been shown to be related to the level of protection conferred which may explain variation between individuals [36]. There is also evidence that saliva protects against dietary acids to a greater extent than stomach acids [5]. However, recent evidence suggests that saliva’s ability to remineralise eroded dental tissue is limited. Both artificial and natural saliva have been observed to increase the surface hardness of enamel and dentine following an erosive challenge [37–39]. However, although some degree of rehardening occurs, recent papers are reporting that limited meaningful remineralisation occurs. Studies have shown no additional protective effect against abrasion with 2–4 h intraoral remineralisation time [15, 40]. Proteins within saliva can interfere with the remineralisation process, binding to enamel and acting as a barrier to remineralisation [15, 41]. Laboratory studies have demonstrated that saliva offers a protective role against erosive challenges resulting in less bulk loss but leaving behind a softer structure [42]. Those with reduced salivary flow or altered salivary composition have anecdotally reported to experience increased dentine hypersensitivity and this may be due to their reduced ability to form a sealing smear layer. Although further work is required in this area, the evidence would suggest that saliva has an important role acting as a barrier but a limited role in any reparative mechanism.

76

S. O’Toole and O. Addison

6.4.3 T  hird Line of Defence Against Dentine Hypersensitivity: Secondary/Tertiary Dentine During active abrasion, attrition or particularly erosion, dentine hypersensitivity is commonly reported [31, 33, 43]. However, it is interesting that dentine hypersensitivity is not the most common presenting complaint amongst those with severe erosive tooth wear [44]. Clinical cases with high levels of exposed dentine and near pulpal exposures can often be vital but not hypersensitive [44]. In the same respect, patients may present with dentine hypersensitivity and no tooth wear [33]. When there are normal rates of physiological tooth wear, this allows time for the pulp to lay down reparative or secondary dentine. This less-organised dentine has reduced fluid flow within the tubules and reduces dentine hypersensitivity as the dental tissue is gradually worn away [45]. This would explain how severely worn teeth with very little protective dentine can remain both vital and with normal or reduced levels of sensitivity. If erosive tooth wear progresses at a relatively stable rate, periapical pathology that is asymptomatic is commonly observed [44].

6.5

Prevention

6.5.1 Limiting Acid Exposure Given that acids, either extrinsic from the diet or intrinsic from the stomach, remove protective tooth substance and the smear layer, it could be argued that limiting exposure to acids is the single most important aspect of preventing dentine hypersensitivity and erosive tooth wear. Duration of acid exposure [33] in addition to frequency of acid exposure [43] has been shown to be associated with dentine hypersensitivity and it is worth counselling patients on both of these aspects. It is important to check for sources of dietary acids that are uncommonly acknowledges by patients such as fruit teas, fruit-flavoured water and fruit-flavoured or acidic sweets. It is also important to check for fruit grazing habits such as chopping fruit into small pieces or snacking slowly on punnets of grapes/ berries.

6.5.2 Limiting Aggressive Mechanical Exposure The amount of dentine removed has been shown to be related to the frequency of brushing, the abrasivity of the dentifrice and the force of brushing. Although there are difficulties in assessing toothbrushing habits, evidence suggests that the first toothbrushing site receives the most brushing time and the last site receives the least. Due to difficulties with accurately measuring wear and comparing dentine hypersensitivity in vivo, no high quality randomised controlled trials have been performed assessing the impact of these variables. Laboratory and in situ

6  Physiology of Erosive Tooth Wear and Relationship with Dentine Hypersensitivity

77

evidence would suggest that choosing a low-medium abrasivity toothpaste and using a low toothbrushing force would minimise dentine hypersensitivity. Brushing immediately after an acid challenge does increase the tooth structure removed. However, little is known and about whether this tooth structure would not be removed under normal physiological functioning. Regardless of the timing of when you brush, it is important to choose less aggressive brushing techniques [46]. The role of bruxism and clenching in dentine hypersensitivity is under-­ investigated. The additional tactile stimulation may stimulate the A delta fibres or continued low grade stimulation may cause a lower firing threshold. Some epidemiological studies have observed parafunctional behaviour to be associated with dentine hypersensitivity [47, 48]. From a clinical perspective, it would be prudent to attempt to control parafunctional activity to prevent erosive tooth wear. This may in turn impact on dentine hypersensitivity.

6.5.3 The Role of Fluoride Although fluorapatite is less soluble than hydroxyapatite, fluoride incorporation into the dental structure has been observed to have a relatively weak protective effect against acid erosion compared with caries [49]. Although the presence of available fluoride ions does have a protective effect [49], the presence of calcium fluoride deposits may also be limited with fluoride covering no more than 40% of an enamel surface even under optimum conditions [50]. Furthermore, retention of fluoride precipitates is unlikely during repeated or severe erosive challenges, even when high fluoride varnish is used [51, 52]. It is likely that fluoride alone will not prevent erosive tooth wear and dentine hypersensitivity in aggressive acidic environments but remains an essential part of a holistic prevention plan.

6.5.4 The Role of Tubule Occluding Agents Tubule occluding agents, predominantly found in dentifrices, can be very effective at occluding dentinal tubules. However, the stability of these agents is not ideal, particularly with erosion and abrasion challenges. Frequent application is often necessary with symptoms returning when use ceases. A recent systematic review and meta-analysis supported the use of toothpastes containing potassium, stannous fluoride, potassium and strontium, potassium and stannous fluoride, calcium sodium phosphosilicate, arginine, and nanohydroxyapatite to relieve dentine hypersensitivity [53]. There was limited evidence to suggest that strontium and amorphous calcium phosphate were effective tubule occluding agents [53]. There is a growing community of clinicians advocating for the use of lasers to occlude tubules. However, this is expensive and the evidence is limited to suggest that lasers offer any advantage over conventional topical desensitising agents [54].

78

S. O’Toole and O. Addison

6.5.5 The Role of Dentine Bonding Agents The use of dentine bonding agents to prevent dentine hypersensitivity and tooth wear has also been tested. Although the etch and rinse technique removes the smear layer and opens the tubules, it then attempts to seal them by hybridising with the inter-tubular dentine to form strong retentive plugs. These plugs would theoretically prevent fluid movement thus stopping any pain. However, dentine adhesive resins are not effective at entirely reducing dentine permeability, particularly when compared with the smear layer [27]. They do not last for a long period of time when exposed intraorally, and are not sufficient to reduce erosive tooth wear progression [55]. Once the dentine bonding agent is lost, it will leave behind a widened tubule with decreased peritubular dentine, increasing the sensitivity. Acid etching the surface does erode a significant amount of tooth structure and there is also difficulty in deciding which surface to cover with dentine bonding agent. Etching only the affected area is difficult, potentially painful for the patient and you risk damaging the surrounding dental tissue. Therefore, dentine bonding agents can only be advocated when all other preventive techniques have failed.

6.6

Conclusion

Both erosive tooth wear and dentine hypersensitivity are complex, multi-factorial conditions. However, the underlying processes for both conditions are inter-related with overlapping aetiologies. There is increasing evidence that presenting with dentine hypersensitivity is a sign of active erosive wear. If a patient presents with dentine hypersensitivity in early life, it would be prudent to thoroughly examine their diet, medical history and oral hygiene habits to rule out risk factors for erosive tooth wear. Documenting their current clinical wear status at this stage, either through a clinical index such as the Basic Erosive Wear Examination (BEWE), an intraoral scan, study models or intraoral photographs may aid in patient education and the early detection of erosive tooth wear progression.

References 1. Carvalho TS, Colon P, Ganss C, Huysmans MC, Lussi A, Schlueter N, et al. Consensus report of the European Federation of Conservative Dentistry: erosive tooth wear—diagnosis and management. Clin Oral Investig. 2015;19(7):1557–61. 2. O’Toole S, Bernabé E, Moazzez R, Bartlett D. Timing of dietary acid intake and erosive tooth wear: a case-control study. J Dent. 2017;56:96–104. 3. Houghton JW, Yong JT, Carpenter G, Bartlett D, Moazzez R, O’Toole S. Differences in the natural enamel surface and acquired enamel pellicle following exposure to citric or hydrochloric acid. Caries Res. 2020;21:226–33. 4. West NX, Lussi A, Seong J, Hellwig E. Dentin hypersensitivity: pain mechanisms and aetiology of exposed cervical dentin. Clin Oral Investig. 2013;17(Suppl. 1):S9–19. 5. Schlueter N, Luka B. Erosive tooth wear—a review on global prevalence and on its prevalence in risk groups. Br Dent J. 2018;224(5):364–70.

6  Physiology of Erosive Tooth Wear and Relationship with Dentine Hypersensitivity

79

6. West NX, Sanz M, Lussi A, Bartlett DW, Bouchard P, Bourgeois D.  Prevalence of dentine hypersensitivity and study of associated factors: a European population-based cross-sectional study. J Dent. 2013;41(10):841–51. 7. Lippert F, Parker DM, Jandt KD. Susceptibility of deciduous and permanent enamel to dietary acid-induced erosion studied with atomic force microscopy nanoindentation. Eur J Oral Sci. 2004;112(1):61–6. 8. Goldberg M, Kulkarni AB, Young M, Boskey A. Dentin: structure, composition and mineralization: the role of dentin ECM in dentin formation and mineralization. Front Biosci (Elite Ed). 2011;3:711–35. 9. Absi EG, Addy M, Adams D.  Dentine hypersensitivity: a study of the patency of dentinal tubules in sensitive and non-sensitive cervical dentine. J Clin Periodontol. 1987;14:280–4. 10. Lussi A, Schlueter N, Rakhmatullina E, Ganss C. Dental erosion--an overview with emphasis on chemical and histopathological aspects. Caries Res. 2011;45(Suppl. 1):2–12. 11. Barbour ME, Parker DM, Allen GC, Jandt KD. Human enamel erosion in constant composition citric acid solutions as a function of degree of saturation with respect to hydroxyapatite. J Oral Rehabil. 2005;32(1):16–21. 12. Mylonas P, Austin RS, Moazzez R, Joiner A, Bartlett DW. In vitro evaluation of the early erosive lesion in polished and natural human enamel. Dent Mater. 2018;34(9):1391–400. 13. Bertacci A, Chersoni S, Davidson CL, Prati C. In vivo enamel fluid movement. Eur J Oral Sci. 2007;115(3):169–73. 14. Lussi A, Hellwig E, Klimek J.  Fluorides—mode of action and recommendations for use. [Review]. Schweizer Monatsschrift fur Zahnmedizin. 2012;122(11):1030–42. 15. Lussi A, Lussi J, Carvalho T, Cvikl B. Toothbrushing after an erosive attack: will waiting avoid tooth wear? Eur J Oral Sci. 2014;122(5):353–9. 16. Garberoglio R, Cozzani G. In vivo effect of oral environment on etched enamel: a scanning electron microscopic study. J Dent Res. 1979;58(9):1859–65. 17. Joiner A, Schäfer F, Naeeni MM, Gupta AK, Zero DT. Remineralisation effect of a dual-phase calcium silicate/phosphate gel combined with calcium silicate/phosphate toothpaste on acid-­ challenged enamel in situ. J Dent. 2014;42(Suppl. 1):S53–9. 18. Nassar HM, Lippert F, Eckert GJ, Hara AT. Impact of toothbrushing frequency and toothpaste fluoride/abrasivity levels on incipient artificial caries lesion abrasion. J Dent. 2018;76:89–92. 19. Ferrario VF, Sforza C, Zanotti G, Tartaglia GM. Maximal bite forces in healthy young adults as predicted by surface electromyography. J Dent. 2004;32(6):451–7. 20. Gibbs CH, Mahan PE, Lundeen HC, Brehnan K, Walsh EK, Holbrook WB. Occlusal forces during chewing and swallowing as measured by sound transmission. J Prosthet Dent. 1981;46(4):443–9. 21. Nishigawa K, Bando E, Nakano M. Quantitative study of bite force during sleep associated bruxism. J Oral Rehabil. 2001;28(5):485–91. 22. Wiegand A, Credé A, Tschammler C, Attin T, Tauböck TT.  Enamel wear by antagonistic restorative materials under erosive conditions. Clin Oral Investig. 2017;21(19):2689–93. 23. Silva AG, Martins CC, Zina LG, Moreira AN, Paiva SM, Pordeus I a., et  al. The association between occlusal factors and noncarious cervical lesions: a systematic review. J Dent 2013;41(1):9–16. 24. Schlueter N, Amaechi BT, Bartlett D, Afonso M, Buzalaf R, Saads Carvalho T, et  al. Terminology of erosive tooth wear: consensus report of a workshop organized by the ORCA and the Cariology Research Group of the IADR. Caries Res. 2020;54(1):2–6. 25. Pashley DH. Smear layer: physiological considerations. Oper Dent Suppl. 1984;3:13–29. 26. Kerns DG, Scheidt MJ, Pashley DH, Horner JA, Strong SL, Van Dyke TE. Dentinal tubule occlusion and root hypersensitivity. J Periodontol. 1991;62(7):421–8. 27. Carrilho MR, Tay FR, Sword J, Donnelly AM, Agee KA, Nishitani Y, et  al. Dentine sealing provided by smear layer/smear plugs vs. adhesive resins/resin tags. Eur J Oral Sci. 2007;115(4):321–9. 28. Absi EG, Addy M, Adams D.  Dentine hypersensitivity—the effect of toothbrushing and dietary compounds on dentine in vitro: an SEM study. J Oral Rehabil. 1992;19(2):101–10.

80

S. O’Toole and O. Addison

29. Foget HM, Pashley DH.  Effect of periodontal root planing on dentin permeability. J Clin Periodontol. 1993;20(9):673–7. 30. Rees JS, Loyn T, Rowe W, Kunst Q, Mcandrew R. The ability of fruit teas to remove the smear layer: an in vitro study of tubule patency. J Dent. 2006;34:67–76. 31. Olley RC, Moazzez R, Bartlett DW. The relationship between incisal/occlusal wear, dentine hypersensitivity and time after the last acid exposure in vivo. J Dent. 2015;43(2):248–52. 32. Risnes S, Li C. On the method of revealing enamel structure by acid etching. Aspects of optimization and interpretation. Microsc Res Tech. 2019;82(10):1668–80. 33. O’Toole S, Bartlett D. The relationship between dentine hypersensitivity, dietary acid intake and erosive tooth wear. J Dent. 2017;67:84–7. 34. Mullan F, Paraskar S, Bartlett DW, Olley RC. Effects of tooth-brushing force with a desensitising dentifrice on dentine tubule patency and surface roughness. J Dent. 2017;60:50–5. 35. Li H, Liu MC, Deng M, Moazzez R, Bartlett DW.  An experiment on the attrition of acid demineralized dentine in vitro. Aust Dent J. 2011;56(1):63–7. 36. Mutahar M, O’Toole S, Carpenter G, Bartlett D, Andiappan M, Moazzez R. Reduced statherin in acquired enamel pellicle on eroded teeth compared to healthy teeth in the same subjects: an in-vivo study. PLoS One. 2017;12(8):1–11. 37. Amaechi BT, Higham SM. In vitro remineralisation of eroded enamel lesions by saliva. J Dent. 2001;29(5):371–6. 38. Attin T, Buchalla W, Gollner M, Hellwig E.  Use of variable remineralization periods to improve the abrasion resistance of previously eroded enamel. Caries Res. 2000;34(1):48–52. 39. Attin T, Knöfel S, Buchalla W, Tütüncü R. In situ evaluation of different remineralization periods to decrease brushing abrasion of demineralized enamel. Caries Res. 2001;35(3):216–22. 40. Ganss C, Schlueter N, Friedrich D, Klimek J. Efficacy of waiting periods and topical fluoride treatment on toothbrush abrasion of eroded enamel in situ. Caries Res. 2007;41(2):146–51. 41. Lussi A, Crenshaw MA, Linde A. Induction and inhibition of hydroxyapatite formation by rat dentine phosphoprotein in vitro. Arch Oral Biol. 1988;33(9):685–91. 42. O’Toole S, Mistry M, Mutahar M, Moazzez R, Bartlett D. Sequence of stannous and sodium fluoride solutions to prevent enamel erosion. J Dent. 2015;43(12):1498–503. 43. Scaramucci T, de Almeida Anfe TE, da Silva FS, Frias AC, Sobral MAP. Investigation of the prevalence, clinical features, and risk factors of dentin hypersensitivity in a selected Brazilian population. Clin Oral Investig. 2014;18(2):651–7. 44. Wazani BE, Dodd MN, Milosevic A. The signs and symptoms of tooth wear in a referred group of patients. Br Dent J. 2012;213(6):E10. 45. Krauser J. Hypersensitive teeth. Part I: Etiology. J Prosthet Dent. 1986;56(2):153–6. 46. West NX, Hooper SM, O’Sullivan D, Hughes N, North M, Macdonald EL, et al. In situ randomised trial investigating abrasive effects of two desensitising toothpastes on dentine with acidic challenge prior to brushing. J Dent. 2012;40(1):77–85. 47. Mafla A, Lopez-Moncayo L. Dentine sensitivity risk factors: a case–control study. Eur J Dent. 2016;10(1):1–6. 48. Alvarez-Arenal A, Alvarez-Menendez L, Gonzalez-Gonzalez I, Jiménez-Castellanos E, Garcia-­ Gonzalez M, DeLlanos-Lanchares H.  The role of occlusal factors in the presence of noncarious cervical lesions in young people: a case-control study. Oper Dent. 2019;44(1):E12–22. 49. Ogaard B, Rölla G, Ruben J, Dijkman T, Arends J. Microradiographic study of demineralization of shark enamel in a human caries model. Scand J Dent Res. 1988;96(3):209–11. 50. Koeser J, Carvalho TS, Pieles U, Lussi A. Preparation and optimization of calcium fluoride particles for dental applications. J Mater Sci Mater Med. 2014;25:1671–7. 51. Austin RS, Stenhagen KR, Hove LH, Dunne S, Moazzez R, Bartlett DW, et al. A qualitative and quantitative investigation into the effect of fluoride formulations on enamel erosion and erosion-abrasion in vitro. J Dent. 2011;39(10):648–55. 52. Austin RS, Stenhagen KR, Hove LH, Tveit AB, Moazzez R, Bartlett DW. The effect of single-­ application fluoride treatment on simulated gastric erosion and erosion-abrasion of enamel in vitro. Int J Prosthodont. 2014;27(5):425–6.

6  Physiology of Erosive Tooth Wear and Relationship with Dentine Hypersensitivity

81

53. Hu ML, Zheng G, Zhang YD, Yan X, Li XC, Lin H. Effect of desensitizing toothpastes on dentine hypersensitivity: a systematic review and meta-analysis. J Dent. 2018;75:12–21. Elsevier Ltd 54. Zhou K, Liu Q, Yu X, Zeng X. Laser therapy versus topical desensitising agents in the management of dentine hypersensitivity: a meta-analysis. Oral Dis. 2021;27(3):422–30. 55. Azzopardi A, Bartlett DW, Watson TF, Sherriff M. The surface effects of erosion and abrasion on dentine with and without a protective layer. Br Dent J. 2004;196(6):351–4. discussion 339

7

Associations Between Tooth Wear and Dental Sleep Disorders: An Overview Peter Wetselaar and Frank Lobbezoo

Abbreviations AHI CHI DISE GORD MAD OSAS PPI SB TWES

7.1

Apnoea-hypopnoea index Cumulative hypersensitivity Index Drug induced sleep/sedation endoscopy Gastro-oesophageal reflux disease Mandibular advancement device Obstructive sleep apneoa syndrome Proton pump inhibitors Sleep bruxism Tooth wear evaluation system

Tooth Wear

Tooth wear is a multifactorial condition, leading to the loss of dental hard tissues, viz., enamel, dentine, and cementum [1]. Tooth wear is an umbrella term with two main subtypes including chemical (erosive) tooth wear and mechanical tooth wear. Both subtypes are further subdivided into intrinsic and extrinsic [2]. This means that there are a total of four subtypes as follows: intrinsic chemical tooth wear (due to stomach acid; also known as erosion), extrinsic chemical tooth wear (due to an erosive diet; also known as erosion), intrinsic mechanical tooth wear (due to tooth-to-­ tooth contact, through function or bruxism; also known as attrition), and extrinsic P. Wetselaar (*) · F. Lobbezoo Department of Orofacial Pain and Dysfunction, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and Vrije Universiteit Amsterdam, Amsterdam, The Netherlands e-mail: [email protected]; [email protected] © Springer Nature Switzerland AG 2022 A. Eder, M. Faigenblum (eds.), Tooth Wear, BDJ Clinician’s Guides, https://doi.org/10.1007/978-3-030-86110-0_7

83

84

P. Wetselaar and F. Lobbezoo

mechanical wear (due to other reasons, like nail biting, pen biting, tooth brushing, etc.; also known as abrasion). The traditional terms describing subtypes of tooth wear (viz., erosion, attrition, and abrasion) have been used for a long period of time, but the newly proposed names of the subtypes are the next step forward to emphasise the multifactorial nature of tooth wear [3]. It should be noted that single wear mechanisms rarely act alone but interact with each other [1]. There is evidence that an acidic diet plays an increasingly important role in the multifactorial condition of tooth wear [4]. This is also a common belief amongst dental clinicians, but actually having knowledge of the entire aetiological spectrum is of the utmost importance. According to the literature, the severity of tooth wear in adults increases with age, and the prevalence of tooth wear in adult populations is increasing, although data are scarce and contradictory [5–8]. A broad range of prevalence figures, viz., between 20% and 45%, has been reported, which may be due to different assessment methods and different study populations [8]. Regarding the diagnosis of tooth wear, a comprehensive approach is necessary due to its multifactorial origin and manifestation. The Tooth Wear Evaluation System (TWES) describes how to implement a systematic approach to the diagnosis (qualification and quantification) and management of the condition [2]. Early diagnosis, adequate preventive measures, and state-of-the-art management are key, in order to limit the loss of dental hard tissues as much as possible [2, 9].

7.2

Dental Sleep Disorders

Besides their critical role in the diagnosis, prevention, and management of tooth wear, dentists are also increasingly confronted with patients with dental sleep disorders [10]. Recently, a new definition of Dental Sleep Medicine was proposed [11]: ‘Dental Sleep Medicine is the discipline concerned with the study of the oral and maxillofacial causes and consequences of sleep-related problems’. The five sleep-related problems to which this definition of Dental Sleep Medicine refers, are: orofacial pain; oral moistening disorders (both oral dryness and oral wetness; in this chapter, we focus on oral dryness); gastro-oesophageal reflux disease (GORD); sleep-related breathing disorders (including snoring and obstructive sleep apnoea syndrome, OSAS; in this chapter, we focus on OSAS); and mandibular movement disorders (including dyskinesia, dystonia, and sleep bruxism; in this chapter, we focus on sleep bruxism). As is the case with tooth wear, prevalence figures for dental sleep disorders also differ a lot between studies, which is again most likely due to different study populations and a wide variety of assessment tools (see Table 7.1). In a recently narrative overview of the literature, the possible associations between tooth wear and the five dental sleep disorders were unravelled [12]. This narrative provides dental professionals with a better comprehension of the possible aetiological factors of tooth wear in their patients and thus improves the approaches to dental care. The aim of this chapter is to discuss the associations between tooth wear and dental sleep disorders.

7  Associations Between Tooth Wear and Dental Sleep Disorders: An Overview

85

Table 7.1  Description of tools used to diagnose tooth wear and the various dental sleep disorders Condition Assessment tool Tooth To assess tooth wear, qualification and quantification are necessary. Qualification wear (to recognise and distinguish between the different sub-forms of tooth wear) is difficult and in the majority of the studies not performed. Regarding the qualification of tooth wear, there is no consensus at this time, although several proposals exist [2]. Quantification (grading the severity of tooth wear) is performed in many different ways, with an equal number of different indices or evaluation systems, also here without consensus [2] Orofacial Dental pain or hypersensitivity can be assessed by oral history taking, pain questionnaires, several dental tests and the use of an index, the Cumulative Hypersensitivity Index (CHI) [41, 42] Oral Hyposalivation can be determined by quantifying the unstimulated or stimulated dryness whole saliva (sialometry). Since there is a great variability in individual salivary flow rates and a wide range of flow rate is accepted, the accurate assessment of salivary dysfunction can be difficult. It can, therefore, be argued whether measurement of salivary flow rates can be used as a valid, discriminating tool [15]. In addition, a wide variety of tests are available, like secretion tests (sialometry, sialo chemistry, oral Schirmer’s test, and so on), mucosal/surface test, functional tests, glandular morphology (scintigraphy or sialography), and questionnaires or interviews [15, 43] GORD Gastro-oesophageal reflux disease (GORD) is a complex disease with a heterogenous symptom profile. Assessment is performed by clinical history taking, questionnaires, response to antisecretory therapy, and different tools like endoscopy, pH monitoring (wire or wireless over 24, 48 and 96 hours), and/or multichannel intraluminal impedance-pH [44]. All assessment tools have their limitations, because there are no universal cut off criteria [20, 44]. Additional signs and symptoms must be present, like heartburn, regurgitation, chest pain, chronic cough, and hoarseness as mentioned in the Montreal definition [20] OSAS The diagnosis of obstructive sleep apnoea syndrome (OSAS) requires the combined assessment of the objective demonstration of abnormal breathing during sleep and relevant clinical features (signs and symptoms). The golden standard for diagnosing the objective abnormal sleep is a polysomnography (at home or in a sleep laboratory), after which the severity is determined by calculating the Apnoea-­ Hypopnoea index (AHI). By means of a drug-induced sleep/sedation endoscopy (DISE), the obstruction sites can be determined Relevant clinical features (signs and symptoms) during sleep are snoring, witnessed apnoea by the bed-partner, choking or gasping, recurrent awakenings, and insomnia. During wakefulness, these are daytime sleepiness, unrefreshing sleep, fatigue, memory/concentration impairment, personality changes, morning nausea, and morning headaches. Structured interviewing and/or questionnaires can reveal these clinical features [31] Sleep Sleep bruxism can be assessed as follows: (1) non-instrumental approaches include bruxism self-report (questionnaires, oral history) and clinical inspection. No consensus is present regarding these approaches. (2) instrumental approaches are electromyographic recordings (including other measures used in somnography or polysomnography; audio and/or video recordings can supplement EMG data). No consensus is present regarding cut-off points of the findings The grading system is as follows: 1. possible sleep bruxism is based on a positive self-report only; 2. probable sleep bruxism is based on a positive clinical inspection, with or without a positive self-report; and 3. definite sleep bruxism is based on a positive instrumental assessment, with or without a positive self-report and/or a positive clinical inspection [37, 38]

86

7.3

P. Wetselaar and F. Lobbezoo

 ssociations Between Tooth Wear and Dental A Sleep Disorders

The possible associations between tooth wear (both chemical and mechanical) and orofacial pain, oral dryness, GORD, OSAS, and sleep bruxism are briefly described below. For more details, see [12].

7.3.1 Orofacial Pain and Tooth Wear Orofacial pain is a common and multifactorial condition, with a prevalence of around 5–22% in the general populations [13]. Orofacial pain refers to pain associated with the hard and soft tissues of the head, face, and neck. These tissues, including skin, mucosa, blood vessels, teeth, glands, bone, cartilage, and muscles, send impulses through the trigeminal nerve to be interpreted as pain by the brain circuits that are primarily responsible for the processing of complex behaviour [13]. The complaint of orofacial pain encompasses a diagnostic range from neurogenic, musculoskeletal, and psychophysiological pathology to headaches, cancer, autoimmune phenomenon, and tissue trauma [13]. In general, tooth wear is a slow process, hardly ever resulting in sensitivity and/ or pain, but chemical tooth wear can be associated with dental pain and/or hypersensitivity (Chap. 6). This is seen mostly in young patients (when the tooth wear process develops fast), due to exposure of dentinal tubules, lack of secondary dentine, and large pulps [12].

7.3.2 Oral Dryness and Tooth Wear Saliva is of paramount importance for the maintenance of oral health, and therefore in-depth knowledge amongst healthcare professionals is of great importance [14] (Chap. 4). Oral Moistening Disorders can be divided into having too little or too much saliva, yielding oral dryness and oral wetness, respectively [11]. Oral dryness is a multifactorial condition, with a prevalence that varies from 10% to 80% [14]. The condition can be divided into: 1. hyposalivation: the objective reduction of the salivary flow due to salivary gland hypofunction, which has been defined as an objectively demonstrable reduction in whole and/or individual gland flow rates; and 2. xerostomia: the subjective sensation of oral dryness, which is most commonly associated with salivary gland dysfunction, although it may also occur with normal gland activity. The terms hyposalivation and xerostomia are often incorrectly used interchangeably [15]. Oral wetness refers to hypersalivation (also known as sialorrhea or ptyalism), which is a condition of increased salivary flow [16]. Oral dryness can be associated with mechanical tooth wear (when less saliva causes less lubrication) and chemical tooth wear (when less saliva results in less buffer capacity) [17, 18].

7  Associations Between Tooth Wear and Dental Sleep Disorders: An Overview

87

7.3.3 G  astro-Oesophageal Reflux Disease (GORD) and Tooth Wear The prevalence of GORD is high, ranging from 10% to 40% [19]. In the so-called Montreal definition and classification, GORD is defined as a condition that develops when the reflux of stomach contents causes troublesome symptoms and/or complications. The disease was subclassified into oesophageal and extra-oesophageal syndromes, and the recognition of laryngitis, cough, asthma, and chemical intrinsic tooth wear as possible GORD syndromes [20]. The literature confirms a strong association between GORD and intrinsic chemical tooth wear (Chaps. 4 and 5), and that the severity of the tooth wear seems to be correlated with the severity of GORD symptoms [21–28]. Figures 7.1a, b show a patient with chemical tooth wear due to GORD.

7.3.4 O  bstructive Sleep Apnoea Syndrome (OSAS) and Tooth Wear The prevalence of OSAS, according to general population-based studies, is approximately 3–7% for adult men and 2–5% for adult women [29], but higher figures have been reported [30]. OSAS is the most common type of sleep apnea and is caused by recurrent obstruction of the upper airway. It is characterised by repetitive pauses in breathing during sleep, despite efforts to breathe, and is usually associated with a reduction in blood oxygen saturation [31]. a

b

Fig. 7.1 (a and b) A 39-year-old male attended his dentist for consultation regarding the thinning and chipping of his anterior teeth. He presented with localised extreme tooth wear, with clinical signs indicating the influence of chemical factors (e.g. occlusal ‘cupping’ and ‘cratering’, increased incisal translucency, and preservation of an enamel ‘cuff’ in the gingival crevice). The dentist could not identify an acidic cause in the diet and asked the patient for complaints which could be attributed to GORD (e.g. heartburn, regurgitation, and dysphagia) . These complaints were confirmed by the patient and the dentist advised him to undergo a diagnostic examination regarding possible GORD. The patient was referred by his doctor to a medical specialist, who made a diagnosis of GORD. The patient was treated with proton pump inhibitor medication by his doctor and restorative treatment with direct composite resin was provided by his dentist

88

P. Wetselaar and F. Lobbezoo

A direct association between tooth wear and OSAS cannot be hypothesised, although possible indirect associations between tooth wear and OSAS have been described: OSAS can be indirectly associated with tooth wear in general through oral dryness [12], with chemical tooth wear through GORD [12, 32–34], and with mechanical tooth wear through sleep bruxism [12, 35]. Figure 7.2 shows a patient with mechanical and chemical tooth wear due to oral dryness, associated with OSAS.

7.3.5 Sleep Bruxism (SB) and Tooth Wear The prevalence of SB ranges from 9.7% to 15.9%, depending on the diagnostic methods used [36]. SB is defined as a masticatory muscle activity during sleep that is characterised as rhythmic (phasic) or non-rhythmic (tonic) and is not a movement disorder or a sleep disorder in otherwise healthy individuals [37, 38].

Fig. 7.2  A 64-year-old male attended his dentist for consultation regarding his worn teeth. He presented with generalised severe tooth wear, with clinical signs indicating the influence of mechanical factors (e.g. shiny facets, fracture of cusps and restorations, and wear located at cervical areas of the teeth), and clinical signs indicating the influence of chemical factors (e.g. occlusal ‘cupping’, ‘cratering’ and ‘raised’ restorations). A thorough history revealed complaints possibly associated with oral dryness (like a need to sip drinks frequently while talking or eating, the use of xerogenic medication, and thirst) which was confirmed during the clinical examination (with the dental mirror sticking to the tissues and recent cervical caries). Whilst taking the history, it was revealed that, in the past, the patient suffered from sleep-related tooth grinding (due to stressful life events) and reflux (due to being overweight). The dentist was suspicious for OSAS as well because of the presence of certain risk factors (e.g. male gender, obesity, and smoking) and complaints (e.g. snoring, excessive daytime sleepiness and morning headaches). The patient was referred by his doctor to a sleep laboratory for a polysomnography. A diagnosis of moderate OSAS was made and the patient was treated with a Mandibular Advancement Device (MAD). This treatment resulted in the disappearance of not only the complaints related to OSAS but also of those related to oral dryness. So far, no restorative treatment has been provided

7  Associations Between Tooth Wear and Dental Sleep Disorders: An Overview

89

Fig. 7.3  A 38-year-old male attended his dentist for consultation about his front teeth becoming shorter with less tooth being visible on smiling. He presented with localised severe tooth wear, clearly of mechanical origin (with enamel and dentine wear at the same rate, corresponding features involving the antagonist teeth, and cracks within the enamel). A diagnosis of probable sleep bruxism was made because both the patient and his partner reported tooth grinding during the night, faceting and scalloping of the soft tissues (tongue, cheek and lip), mechanical tooth wear, and morning stiffness in the masticatory muscles. The main aetiological factors were the abuse of drugs (e.g. ecstasy and cocaine) and smoking. Restorative treatment was provided with direct composite resin by his dentist. Following completion, the restored dentition was protected by an occlusal splint

Considering the possible associations between SB and tooth wear, it is known that tooth wear does not cause bruxism [39, 40], and existing tooth wear is not a valid tool for the diagnosis of sleep bruxism, because of tooth wear being a multifactorial condition [12]. Nevertheless, there is evidence that bruxism is associated with mechanical tooth wear [39]. Figure 7.3 shows a patient with mechanical tooth wear due to sleep bruxism.

7.4

Conclusion

Tooth wear and dental sleep disorders are associated with each other, and all are common multifactorial conditions. Since the dental sleep disorders are interlinked, their consequences are difficult to disentangle. When several sleep disorders are present at the same time, they can have a synergetic effect accelerating the tooth wear process. The knowledge described in this chapter can support dental clinicians in determining the aetiological factors of the identified tooth wear in their patients, and thus improve the provision of preventive advice and dental care. Only a comprehensive approach can result in state-of-the-art diagnostic processes and optimal care outcomes.

90

P. Wetselaar and F. Lobbezoo

References 1. Shellis RP, Addy M. The interactions between attrition, abrasion and erosion in tooth wear. Monogr Oral Sci. 2014;25:32–45. Review 2. Wetselaar P, Lobbezoo F.  The Tooth Wear Evaluation System (TWES): a modular clinical guideline for the diagnosis and management planning of worn dentitions. J Oral Rehabil. 2016;43:69–80. Review 3. Wetselaar P, Lobbezoo F, Beddis H.  Restorative dentistry: tooth wear terms. Br Dent J. 2018;225:94. 4. Johansson AK, Omar R, Carlsson GE, Johansson A. Dental erosion and its growing importance in clinical practice: from past to present. Int J Dent. 2012;2012:632907. 5. Van’t Spijker A, Rodriguez JM, Kreulen CM, Bronkhorst EM, Bartlett DW, Creugers NH. Prevalence of tooth wear in adults. Int J Prosthodont. 2009;22:35–42. 6. Jaeggi T, Lussi A.  Prevalence, incidence and distribution of erosion. Monogr Oral Sci. 2014;25:55–73. Review 7. Wetselaar P, Vermaire JH, Visscher CM, Lobbezoo F, Schuller AA. The Prevalence Of Tooth wear in the Dutch adult population. Caries Res. 2016;50:543–50. 8. Schlueter N, Luka B. Erosive tooth wear-a review on global prevalence and on its prevalence in risk groups. Br Dent J. 2018;224:364–70. Review 9. Loomans B, Opdam N, Attin T, Bartlett D, Edelhoff D, Frankenberger R, Benic G, Ramseyer S, Wetselaar P, Sterenborg B, Hickel R, Pallesen U, Mehta S, Banerji S, Lussi A, Wilson N. Severe tooth wear: European Consensus Statement on Management Guidelines. J Adhes Dent. 2017;19:111–9. 10. Lavigne GJ, Goulet JP, Zuconni M, Morrison F, Lobbezoo F.  Sleep disorders and the dental patient: an overview. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 1999;88:257–72. Review 11. Lobbezoo F, Aarab G, Wetselaar P, Hoekema A, de Lange J, de Vries N. A new definition of dental sleep medicine. J Oral Rehabil. 2016;430:786–90. 12. Wetselaar P, Manfredini D, Ahlberg J, Johansson A, Aarab G, Papagianni CE, Reyes Sevilla M, Koutris M, Lobbezoo F. Associations between tooth wear and dental sleep disorders: a narrative overview. J Oral Rehabil. 2019;46:765–75. Review 13. de Leeuw R, Klasser GD, editors. Orofacial pain. Guidelines for assessment, diagnosis, and management, The American Academy of Orofacial Pain. 6th ed. Chicago, IL: Quintessence Publishing Co, Inc.; 2018. 14. Llena-Puy C. The rôle of saliva in maintaining oral health and as an aid to diagnosis. Med Oral Patol Oral Cir Bucal. 2006;11:E449–55. 15. Löfgren CD, Wickström C, Sonesson M, Lagunas PT, Christersson C. A systematic review of methods to diagnose oral dryness and salivary gland function. BMC Oral Health. 2012;12:29. Review 16. Boyce HW, Bakheet MR. Sialorrhea: a review of a vexing, often unrecognized sign of oropharyngeal and esophageal disease. J Clin Gastroenterol. 2005;39:89–97. 17. Hara AT, Zero DT. The potential of saliva in protecting against dental erosion. Monogr Oral Sci. 2014;25:197–205. Review 18. Young WG. The oral medicine of tooth wear. Aust Dent J. 2001;46:236–50. Review 19. Boeckxstaens G, El-Serag HB, Smout AJ, Kahrilas PJ. Symptomatic reflux disease: the present, the past and the future. Gut. 2014;63:1185–93. 20. Vakil N, van Zanten SV, Kahrilas P, Dent J, Jones R, Global Consensus Group. The Montreal definition and classification of gastroesophageal reflux disease: a global evidence-based consensus. Am J Gastroenterol. 2006;101:1900–20. 21. Pace F, Pallotta S, Tonini M, Vakil N, Bianchi PG.  Systematic review: gastro-oesophageal reflux disease and dental lesions. Aliment Pharmacol Ther. 2008;27:1179–86. Review 22. Moazzez R, Bartlett D. Intrinsic causes of erosion. Monogr Oral Sci. 2014;25:180–96. Review 23. Schlueter N, Tveit AB.  Prevalence of erosive tooth wear in risk groups. Monogr Oral Sci. 2014;25:74–98. Review

7  Associations Between Tooth Wear and Dental Sleep Disorders: An Overview

91

24. Marsicano JA, de Moura-Grec PG, Bonato RC, de Carvalho Sales-Peres M, Sales-Peres A, Sales-Peres SH. Gastroesophageal reflux, dental erosion, and halitosis in epidemiological surveys: a systematic review. Eur J Gastroenterol Hepatol. 2013;25:135–41. Review 25. Ranjitkar S, Smales RJ, Kaidonis JA. Oral manifestations of gastroesophageal reflux disease. J Gastroenterol Hepatol. 2012;27:21–7. Review 26. Moazzez R, Bartlett D, Anggiansah A. Dental erosion, gastro-oesophageal reflux disease and saliva: how are they related? J Dent. 2004;32:489–94. 27. Yoshikawa H, Furuta K, Ueno M, Egawa M, Yoshino A, Kondo S, Nariai Y, Ishibashi H, Kinoshita Y, Sekine J.  Oral symptoms including dental erosion in gastroesophageal reflux disease are associated with decreased salivary flow volume and swallowing function. J Gastroenterol. 2012;47:412–20. 28. Saksena R, Bartlett DW, Smith BG.  The role of saliva in regurgitation erosion. Eur J Prosthodont Restor Dent. 1999;7:121–4. 29. Punjabi NM.  The epidemiology of adult obstructive sleep apnea. Proc Am Thorac Soc. 2008;5:136–43. 30. Senaratna CV, Perret JL, Lodge CJ, Lowe AJ, Campbell BE, Matheson MC, Hamilton GS, Dharmage SC. Prevalence of obstructive sleep apnea in the general population: a systematic review. Sleep Med Rev. 2017;34:70–81. Review 31. Anon. Sleep-related breathing disorders in adults: recommendations for syndrome definition and measurement techniques in clinical research. The Report of an American Academy of Sleep Medicine Task Force. Sleep. 1999;22:667–89. 32. Durán-Cantolla J, Alkhraisat MH, Martínez-Null C, Aguirre JJ, Guinea ER, Anitua E. Frequency of obstructive sleep apnea syndrome in dental patients with tooth wear. J Clin Sleep Med. 2015;11:445–50. 33. Zanation AM, Senior BA. The relationship between extraesophageal reflux (EER) and obstructive sleep apnea (OSA). Sleep Med Rev. 2005;9:453–8. Review 34. Emilsson ÖI, Bengtsson A, Franklin KA, Torén K, Benediktsdóttir B, Farkhooy A, Weyler J, Dom S, De Backer W, Gislason T, Janson C. Nocturnal gastro-oesophageal reflux, asthma and symptoms of OSA: a longitudinal, general population study. Eur Respir J. 2013;41:1347–54. 35. Manfredini D, Guarda-Nardini L, Marchese-Ragona R, Lobbezoo F.  Theories on possible temporal relationships between sleep bruxism and obstructive sleep apnea events. An expert opinion. Sleep Breath. 2015;19:1459–65. Review 36. Manfredini D, Winocur E, Guarda-Nardini L, Paesani D, Lobbezoo F. Epidemiology of bruxism in adults: a systematic review of the literature. J Orofac Pain. 2013;27:99–110. 37. Lobbezoo F, Ahlberg J, Raphael KG, Wetselaar P, Glaros AG, Kato T, Santiago V, Winocur E, De Laat A, De Leeuw R, Koyano K, Lavigne GJ, Svensson P, Manfredini D. Assessment of bruxism: the international consensus revisited. J Oral Rehabil. 2018;45:837–44. 38. Manfredini D, Ahlberg J, Aarab G, Bracci A, Durham J, Ettlin D, Gallo LM, Koutris M, Wetselaar P, Svensson P, Lobbezoo F.  Towards a Standardized Tool for the Assessment of Bruxism (STAB): overview and general remarks of a multidimensional bruxism evaluation system. J Oral Rehabil. 2020;47(5):549–56. https://doi.org/10.1111/joor.12938. 39. Lobbezoo F, Ahlberg J, Manfredini D, Winocur E. Are bruxism and the bite causally related? J Oral Rehabil. 2012;39:489–501. Review 40. Lobbezoo F, Naeije M. Bruxism is mainly regulated centrally, not peripherally. J Oral Rehabil. 2001;28:1085–91. Review 41. West NX, Sanz M, Lussi A, Bartlett D, Bouchard P, Bourgeois D. Prevalence of dentine hypersensitivity and study of associated factors: a European population-based cross-sectional study. J Dent. 2013;41:841–51. 42. Olley RC, Moazzez R, Bartlett D.  The relationship between incisal/occlusal wear, dentine hypersensitivity and time after the last acid exposure in vivo. J Dent. 2015;43:248–52. 43. Thomson WM, Chalmers JM, Spencer AJ, Williams SM. The Xerostomia Inventory: a multi-­ item approach to measuring dry mouth. Community Dent Health. 1999;16:12–7. 44. Gyawali CP, Kahrilas PJ, Savarino E, Zerbib F, Mion F, Smout AJPM, Vaezi M, Sifrim D, Fox MR, Vela MF, Tutuian R, Tack J, Bredenoord AJ, Pandolfino J, Roman S. Modern diagnosis of GERD: the Lyon Consensus. Gut. 2018;67:1351–62. Review

8

Dento-Legal Considerations in the Management of Patients with Tooth Wear Len D’Cruz

8.1

Introduction

Even a cursory look at the publications from the defence organisations will seldom highlight tooth wear as the source of clinical negligence claims against dental professionals. Far surpassing tooth wear will be claims relating to implants, endodontics and periodontal disease diagnosis and management. That might suggest that clinicians are very attuned to tooth wear and that because they diagnose it and manage it so well, no claims arise from this particular area of clinical dentistry. In fact, the opposite is true. It appears that dental professionals do not seem to be aware of the current guidelines. For example, amongst a cohort of general dental practitioners, none had heard of or used the Smith and Knight index, only 10% were aware of the Basic Erosive Wear Examination (BEWE) and 65% were unaware of any guidelines on monitoring tooth wear [1]. Chapters 1 and 2 have set out the increasing prevalence of tooth wear and its effects on adults and increasingly in younger age groups caused by the erosive nature of soft drinks including both fruit juice and carbonated drinks. Tooth wear is largely a silent disease and many patients may present without any symptoms or concerns regarding wear to their teeth. Often patients simply attribute it to normal physiological wear and the natural signs of ageing. They are therefore less likely to blame anyone if a diagnosis is made ‘late’. When patients do attend with issues, aesthetic concerns are the most prevalent presenting concern, followed by sensitivity [2]. Just because patients do not complain or make claims against clinicians in relation to tooth wear does not mean it is not important. Failure to prevent and manage active tooth wear is contrary to the patient-centred, preventively orientated L. D’Cruz (*) Head of Indemnity, British Dental Association and General Dental Practitioner, Woodford Dental Care, London, Essex, UK e-mail: [email protected] © Springer Nature Switzerland AG 2022 A. Eder, M. Faigenblum (eds.), Tooth Wear, BDJ Clinician’s Guides, https://doi.org/10.1007/978-3-030-86110-0_8

93

94

L. D’Cruz

minimum intervention philosophies and concepts driving current trends in clinical practice [3]. It may ultimately increase the financial and biological burden on patients who will have to deal with potentially more complex problems such as loss of vertical dimension, sensitivity and compromised aesthetics later on.

8.2

Examination and History

Guidance on the process and importance of taking a thorough history, undertaking a comprehensive clinical assessment and arriving at a diagnosis is provided in Chaps. 1, 9 and 10. Three opening questions [4] that dental professionals can use routinely for all patients, including new and recall patients, will assist also in identifying patients with worn teeth. • Do you have any pain, discomfort or sensitivity? • Do you have any difficulty chewing or eating (functional problems)? • Do you have any concerns with the appearance of your teeth? A negative response does not mean that there are no tooth wear issues, simply that they may be unaware of it. For example, palatal wear will not be visible to the patient. Positive responses will need careful attention. For example, sensitivity could mean that erosion is progressing actively and will need some management.

8.3

Medical History

The patient should complete and sign a written medical history. This should be checked by the clinician and signed as having been checked. The medical history should be updated on a regular basis. There are some key features of a medical history that might be suggestive of tooth wear problems (Chap. 5). These include gastro-­oesophageal reflux disease (GORD), hiatus hernia prescribed medication such as proton-pump inhibitors or omeprazole currently or historically, frequent use of asthma inhalers containing steroid or effervescent medications. Bulimic or anorexic patients may be understandably reluctant to disclose their conditions and so a sensitive approach needs to be taken if this is suspected following clinical examination. Patients who have impaired salivary function or xerostomia should be highlighted as being at risk. Further guidance on medical conditions relating to tooth wear can be found in earlier chapters.

8.4

Severity

The location and severity of any tooth wear should be recorded in the clinical records. The most commonly used scale is the Basic Erosive Wear Examination (BEWE) index [5]. Along with caries and periodontal disease, it is difficult to justify not screening for tooth wear as part of an overall risk assessment for every patient.

8  Dento-Legal Considerations in the Management of Patients with Tooth Wear

95

Tooth wear assessment is an integral part of the Oral Health Assessment (OHA) that is used as the bedrock of the clinical risk screening component in primary care in England and Wales [6]. Along with dental caries, periodontal disease and risks associated with soft tissue findings, non-carious tooth wear forms a RAG (red-­amber-­green) scoring for the patient in each of these domains. This allows a dental practitioner to produce an overall risk assessment for the oral health of the patient. For tooth wear, the software programmes can prompts the clinician to ask the following social history questions that relate to this domain: • Do you have a fizzy or acidic diet? • Do you suffer from reflux or eating disorder? Following a comprehensive clinical examination, the clinician should assess: • • • • • •

Unsatisfactory tooth brushing technique? Parafunction? Caries—arrested/active/free Plaque control Tooth wear Restoration level in mouth

The computer algorithm that was used in the NHS pilot and prototype programme in England and Wales up until 2022 helped the clinician devise a self-care plan to communicate with patients including an awareness of their self-responsibility. Pilots aligned with this assessment protocol commenced in July 2011 and transitioned to prototypes in 2016 [7]. It is now likely that it will be considered standard practice for dental practitioners to carry out these types of risk assessments in clinical practice (Chap. 3). The defining factor in risk assessment should be the presence of a BEWE score of 3. This is a sign of advanced wear at any age and the underlying aetiology needs to be diagnosed and managed [8].

8.5

Diagnosis

Recognising that a problem is present and communicating that with the patient is the first important step (Fig. 8.1). Diagnosing the cause of the problem is more challenging as the tooth wear process is often multifactorial and clinicians will need to consider that a variety of aetiological factors are at play in most cases. Equally challenging is establishing whether tooth wear is actively progressing or stable. If seeing a patient for the first time, they may well have lived with the current tooth wear condition for some time and whilst there is a responsibility to report the clinical findings to them, it is important that any description and assessment is done sensitively.

96

L. D’Cruz

Fig. 8.1  Recognising the problem is easy in this case but diagnosing the cause and managing patient expectations may be more challenging

History taking and questioning of patients in practice is sometimes perfunctory especially when the patient is unaware of the tooth wear problem. An attempt at establishing dietary habits are often met with ‘No, I don’t really have acidy things’ and clinicians, having drawn a blank in the rushed environment of general practice check-ups, pursue the matter no further. Some persistence is, therefore, required and there are templates to ask specific focussed questions to aid the diagnostic process. A diagnosis of some description, even if it is a provisional one, should be recorded in the clinical records and communicated to the patient.

8.6

Special Tests

Many practitioners now have access to image capture devices chairside, which continue to improve in terms of quality, as well as high quality digital cameras (Fig. 8.2a, b). With the patient’s consent, clinical photographs can be taken for both recording and comparative purposes, as well as to be able to show the issues to the patient. Looking ahead, 3D imaging will also become increasingly helpful in this regard (Chaps. 1 and 9).

8.7

Management of Risk factors

The next most important thing after recognising the problem and making a diagnosis, is management of the risk factors (Chap. 3). This is very much about disease ownership. Once a diagnosis has been made, the patient can be helped to identify those risk factors with sympathetic advice about lifestyle changes. To do this, the patient needs to be armed with the relevant information and knowledge to make critical behaviour changes. If, for example, the erosion can be attributed to the extrinsic intake of fruit juice or carbonated drink, dietary advice

8  Dento-Legal Considerations in the Management of Patients with Tooth Wear

a

97

b

Fig. 8.2 (a) Intra-oral cameras may not yet give the quality of resolution expected from a (b) high quality digital camera but they continue to improve and are useful to show patients. In these cases, and along with the tooth wear, caries is present and primary disease control is a care priority

will be important. If it relates to harsh mechanical toothbrushing, advice about frequency and force of brushing and abrasivity of toothbrushes and toothpastes will be important to communicate. If leaflets, diet sheets and other information, such as lists of potentially erosive foods and drinks are given to the patient, this should be referenced in the clinical records (e.g. ‘patient given tooth wear advice sheet v2.0’).

8.8

Consent—to Intervene or Not to Intervene—That Is the Question

The strategic approach taken by a dental practitioner in the restorative management of the ravages of tooth wear is a function of many different things. Primarily, it is the competence and familiarity of the dental professional with the restorative technique, their training and their bias for direct or indirect approaches. A philosophy of minimum intervention is one that is now widely advocated. In a sense, a patient can be influenced by a clinician’s use of language, the words they say and how persuasive or confident they are in their communications [9]. The patient is entirely in the hands of the clinician, dependent on their advice and guidance and trusting that it is offered in their best interest. An unconscious bias towards indirect restorations may not be immediately obvious to a patient who will be led by the dental practitioner toward a particular care pathway. It is only in the rare situation that the patient lacks belief in the clinician or their authenticity that they may wish to seek a second opinion. If we are dealing with a patient who has the legal capacity to make a decision on their own, then we have a legal and ethical obligation to explain the risks, benefits and likely outcomes of their care in order to guide their decision-making process.

98

L. D’Cruz

They might be ‘nudged’ in the ‘right’ direction in a benevolent fashion but that is where paternalism and the right to self-determination meets and a clinician should be expected to go no further. Equally, a dental practitioner who lacks confidence or knowledge of extensive tooth wear management may err on the side of caution and persuade the patient that monitoring and reviewing their tooth wear is in their best interest. This can be equally problematic since no treatment may compromise predictability of treatment further down the line. The Montgomery judgement [10] heralded a paradigm shift in the information that a patient should be given with regards to risk. Though this case only brought civil law up-to-date with pre-existing guidance [11] from regulators like the General Dental Council, it bears reflecting here in relation to patients understanding their options with regards to the management of their tooth wear.

8.8.1 S  hould Patients Agree to Monitoring Their Tooth Wear or Should Some Restorative Intervention Take Place? Montgomery reinforced the importance of discussing with the patient, before treatment, the options available to them (including the option of doing nothing) and the risks and benefits of each option. This appears to create a significant responsibility on the clinician to find out, as part of the consent process, what is important to the particular patient sitting in their chair [12]. Montgomery shifted the test from what a dental professional considers appropriate to warn a patient about to what the particular patient would wish to know about the proposed treatment and specifically to be told of the material risks. The test of materiality is whether, in the circumstances of the particular case, a reasonable person in the patient’s position would be likely to attach significance to the risk, or whether the clinician should reasonably be aware that the particular patient would be likely to attach significance to it. What constitutes a material risk will vary from patient to patient and, therefore, consent needs to be patient specific. In the context of tooth wear, some patients (e.g. bulimics) may not wish to have ongoing monitoring of their teeth whilst the invaluable matrix of their enamel continues to erode due to the frequent vomiting of hydrochloric acid with a pH of about 1.0 [13]. Other schools of thought would suggest that only after the patient has demonstrated compliance with advice by checking that erosion is no longer active should any restorative intervention be provided [14]. The fundamental aim in caring for patients with tooth wear is to make a diagnosis and prevent further pathological wear. An early diagnosis followed by an effective preventive programme which is adhered to by the patient together with monitoring over an extended period may be all that is needed. However, monitoring the progression of tooth wear is by no means a simple challenge [14] (Chaps. 1 and 9). Patients need to be provided with all of the relevant information in order to be able to make an informed decision with the help of the clinician. Shared decision

8  Dento-Legal Considerations in the Management of Patients with Tooth Wear

99

making is the conversation that happens between a patient and their healthcare professional to reach a choice together. This conversation needs patients and professionals to understand what is important to the other person when choosing a care option [15].

8.9

Risk and Benefits

If a decision is made to provide interceptive care, the patient must be aware of the benefits and risks of those treatments. Longevity of the restoration will depend on the aetiology of the tooth wear. Where, for example, the problem has arisen from chemical erosion such as fruit juice or carbonated drinks, direct composite restorations would be appropriate since they are resistant to acid attack. Patients need to be aware of the clinical limitation of composite material especially in the hostile environment of incisal edge buildups on worn anterior teeth. Patients need to know that composites protect underlying tooth substrate but may wear, discolour and chip over time. This will incur further visits, time and costs for which patients will need to be consented at the outset. Patients who are busy and want the confidence and security of not having to worry about the aesthetic downsides of a restoration failing suddenly in the aesthetic zone may choose different options if they are made aware of these risks in advance. Patients should also be appraised of the benefits of composite type materials since they have excellent cosmetic properties and are relatively low maintenance for the patient. They do not require expert skills to deliver a reasonable aesthetic result although there are many skilled dental practitioners delivering highly aesthetic results who run courses for colleagues. Patients should be advised that where worn teeth are restored by placing material on the occlusal surfaces, there will be an inevitable change in the occlusion unless space is available. Most patients adapt readily over time to changes in their occlusion using techniques pioneered by Dahl et al. [16] many decades ago (Chaps. 11, 15 and 16). Some, however, do not and clinicians should be aware of this possibility with occlusally aware patients.

8.10 If a Patient Declines Treatment That Is Offered There is no obligation for a patient to accept any treatment offered. An adult of sound mind has the right to choose whether to accept or decline treatment. In extremis, ‘an adult patient has an absolute right to refuse to consent to medical treatment for any reason, rational or irrational, or for no reason at all, even where that decision may lead to his death’ [17]. Dental professionals should explain the implication of declining treatment to the patient and record this in the notes. There is no additional need for a patient to sign any form confirming their acceptance of the risks.

100

L. D’Cruz

8.11 Second Opinion It important that dentists know and understand their own limitations. Obtaining a second opinion to decide what treatment and when it should be provided for a tooth wear patient is of fundamental importance. Similarly, referring patients on for the delivery of any necessary care is a professional obligation and General Dental Council guidance makes this clear [18]: 6.3.3 You should refer patients on if the treatment required is outside your scope of practice or competence. You should be clear about the procedure for doing this. 7.2.2 You should only deliver treatment and care if you are confident that you have had the necessary training and are competent to do so. If you are not confident to provide treatment, you must refer the patient to an appropriately trained colleague.

8.12 Record Keeping Records survive long after the memories of both the patient and the dental practitioner have faded with regard to any particular clinical encounter. How good those records are in recreating the particular examination or treatment, what was said, done or agreed will determine how good any defence can be to any complaint or allegation that care may have fallen below an expected standard. Readers are directed to more comprehensive guidance on record keeping in general [19]. In relation to tooth wear, the key aspects that dental teams need to record are that: –– –– –– –– ––

tooth wear has been identified this finding has been communicated to the patient a diagnosis, where possible, has been made a management strategy is set out and agreed with the patient tooth wear and/or its management are reviewed periodically

Where a patient declines treatment, this should be recorded in the records. The risks and benefits of particular treatments should be noted (e.g. loss of vitality with indirect restorations, wear and tear of restorative materials and costs to repair or replace them as well as occlusal issues) if material changes are made as a result of interventive treatment.

8.13 Conclusion Tooth wear is an issue that dentists will face on an increasingly regular basis in clinical practice. There is an expectation from patients that dental professionals can recognise problems and will either manage them or, where they are unable to do so, will refer them to colleagues who are able to help.

8  Dento-Legal Considerations in the Management of Patients with Tooth Wear

101

In a general dental practice setting, these patients may well have long term needs that run over many years and it can be particularly satisfying to see the benefits of effective prevention and patients with more severe problems restored to good dental health and once again able to eat comfortably, smile and go about their daily lives without worrying about their teeth.

References 1. O’Hara M, Millar B. Evaluation of the assessment of tooth wear by general dental practitioners. Br Dent J. 2020;228:423–8. 2. El Wazani B, Dodd MN, Milosevic A. Br Dent J. 2012;213:E10. 3. Slater L, Eder A, Wilson N. Worning: tooth wear ahead. Prim Dent J. 2016;5(3):38–42. 4. Milosevic A. Acid erosion: an increasingly relevant dental problem-risk factors, management and restoration. Prim Dent J. 2017;6(1):37–44. 5. Aranguiz V, Laar JS, Marro ML, O’Toole S, Ramirez V, Bartlett D. Recommendations and guidelines for dentists using the basic erosive wear examination index (BEWE). Br Dent J. 2020;228:153–7. 6. Dental Contract reform—prototypes Overview document Department of Health 15 January 2015; Dental contract reform: prototypes (publishing.service.gov.uk) 7. Rooney E.  Evaluation of the first year of prototyping 2016–17 Department of Health May 2018; evaluation-­report-­2016-­2017.pdf (publishing.service.gov.uk) 8. O’Toole S, Mylonas P, Bartlett D. Practice based risk assessment-a practical guide for oral healthcare teams: tooth wear. Dent Update. 2019;46:171–8. 9. Say RE, Thomson R. The importance of patient preferences in treatment decision-challnges for doctors. Br Med J. 2003;327:542–5. 10. Montgomery v Lanarkshire Health Board UKSC[2015] UKSC11. 11. Farrell AM, Brazeir M. Not so new directions in the law of consent? Examining Montgomery v Lanarkshire Health Board. J Med Ethics. 2016;42:85–8. 12. Bright E, D’Cruz L, Milne E. Consent—an update. Br Dent J. 2017;222:655–7. 13. Kelleher MG, Blum IR. Facts and fallacies about restorative philosophies for the management of the worn dentition. Prim Dent J. 2020;9(1):27–31. 14. Mehta SB, Banerji S, Millar BJ, Suraez-Feito J-M. Current concepts on the management of tooth wear: Part 1. Assessment, treatment planning and strategies for the prevention and the passive management of tooth wear. Brit Dent J. 2012;212(1):17–27. 15. NHS Shared decision making; http://sdm.rightcare.nhs.uk/about/shared-­decision-­making/ 16. Dahl BL, Krogstad O, Karlsen K. An alternative treatment in cases with advanced localised attrition. J Oral Rehab. 1975;2(3):209–14. 17. (Re MB [1997] 2 F.L.R 426 at 432). 18. Focus on Standards, General Dental Council, UK September 2013: http://standards.gdc-­uk.org 19. Faculty of General Dental Practice. Clinical examination and record keeping: Good practice guidelines. 3rd ed. London: Faculty of General Dental Practice; 2016. https://www.fgdp.org. uk/guidance-­standards/clinical-­examination-­and-­record-­keeping-­0

Part II Management of Tooth Wear

9

A Pragmatic Philosophy of Tooth Wear Management Bas Loomans and Shamir Mehta

9.1

Introduction

As the natural dentition continues to function, with concomitant exposure to erosive, abrasive and attritive factors, wearing-away of the dental hard tissues will take place. Tooth wear, is therefore, an age-related phenomenon [1]. ‘Physiological wear’ is a term that is applied to describe that level of tooth, wear which is expected for the patient’s age, commensurate with normal, day-to-day function [2]. The vertical loss of enamel from physiological wear of the posterior dentition has been estimated to be approximately 15–29 μm per annum [3]. Clinically, however, patients of a similar age will frequently present with marked variation in the severity and pattern of their tooth tissue loss. Given the presence of an ageing western population retaining its natural teeth into advanced years with the cumulative exposure to a plethora of aetiological factors, signs of more severe tooth forms of wear amongst older patients are more likely to be frequently observed in the primary care setting [4]. With changes in lifestyle and dietary habits that have also taken place over the past few decades, to include substantial increases in the consumption of soft beverages [5], tooth wear may also be commonly seen amongst the younger population (Chap. 2). Visible signs of erosive tooth wear were reported by Bartlett et al. [6], at the buccal/facial and lingual/palatal surfaces of just under one-third of a sample of approximately 3200 adults aged 18–35  years, from seven European countries. Furthermore, using the available data, mean global prevalence rates of erosive tooth

B. Loomans (*) Radboud University Medical Center, Nijmegen, The Netherlands e-mail: [email protected] S. Mehta Faculty of Dentistry, Oral and Craniofacial Sciences, King’s College London, London, UK e-mail: [email protected] © Springer Nature Switzerland AG 2022 A. Eder, M. Faigenblum (eds.), Tooth Wear, BDJ Clinician’s Guides, https://doi.org/10.1007/978-3-030-86110-0_9

105

106

B. Loomans and S. Mehta

wear between 20% and 45% in permanent teeth and between 30% and 50% in deciduous teeth, have been more recently estimated [7]. Patients with moderate to severe levels of tooth wear may report and display a variety of symptoms and signs, and for some, the condition can also have an adverse impact on their quality of life [8–13] (Chaps. 1 and 5). Mehta et  al. [13] have recently reported a significant association between the presence of severe tooth wear and a lower oral health-related quality of life amongst new patients attending for a dental examination in the general practice setting. Given the reported prevalence rates and the clinical and psycho-social effects that may be associated with a wearing dentition, it would seem logical for dental professionals to have the necessary diagnostic and managements skills to provide appropriate levels of patient care in the primary care setting. For some patients with tooth wear, complex restorative intervention sometimes involving an increase in the occlusal vertical dimension (OVD) may be indicated [14]. This is unfortunately, not always a simple undertaking. However, as the progression of tooth wear is amenable to prevention [15], the prescription of a tailored preventive plan with vigilant monitoring and counselling may negate, or at the least, defer the need for restorative intervention. The preparation of a tailored preventive plan would usually commence with the identification of the likely aetiological factors. However, as tooth wear often has a multifactorial aetiology (where it may neither be possible to consistently and accurately identify all of the causative factors), the prescription of an appropriate preventive plan may also prove cumbersome. This aim of this chapter is to discuss the principles of a pragmatic philosophy of tooth wear management, based on the ‘Radboud philosophy’ for the management of severe tooth wear [16]. Aspects such as the monitoring and counselling of patients, and the concepts for the conservative and practical approach for the restoration of a worn dentition, will also be addressed.

9.2

The Diagnosis of Tooth Wear

To assist general dental practitioners with their decision making for the management of severe wear cases, a flow chart was developed in a recent European Consensus Meeting (Fig. 9.1). Given the nature of tooth wear as discussed above, clear descriptive terms are needed to enable diagnosis and treatment planning. In 2017, the term the term ‘pathological tooth wear’ was also defined in a European Consensus Statement on the Management Guidelines (for Severe Wear) [17] as ‘tooth wear which is atypical for the age of the patient causing pain or discomfort, functional problems, or deterioration of aesthetic appearance, which if it progresses, may give rise to undesirable complications of increased complexity’. To facilitate the clinical assessment of the levels of tooth wear present, as part of these Guidelines, the term ‘severe tooth wear’, was defined as ‘tooth wear with substantial loss of tooth structure, with dentine exposure and significant loss (more than or equal to one third) of the clinical crown’. Thus, whilst an elderly patient may have signs of severe tooth wear, this

9  A Pragmatic Philosophy of Tooth Wear Management Risk assessment. Consider aetiological factors. Document severity of tooth wear present.

107

Establish appropriate preventive programme with periodic reenforcement, counselling and monitoring

Yes

Pathological

Amount of tooth wear

No

Is tooth wear cause for concern for patient and/or clinician?

Yes

Counselling and monitoring Formulate treatment plan with attainment of informed consent

Physiological Yes

Restorative intervention

No treatment required

Fig. 9.1  Flow chart: decision making process for a patient with tooth

presentation may be typical for age and be of no further concern. In contrast, a younger patient with symptoms of pain associated dentine exposure with signs of early tooth wear associated with active erosion, may be diagnosed with pathological tooth wear that is not severe. As seen in Fig. 9.1, where the presenting tooth wear is physiological (typical for the age of the patient), no further treatment would be indicated. However, for patients with pathological tooth wear (or where there is a suspicion of pathological wear) further diagnostic investigations to include risk assessment, will be required to determine the most appropriate clinical management strategy. Risk assessment for tooth wear requires the identification of the impact and influence of the above aetiological factors, together with an appraisal of the extent of tooth wear present and the likely progression (Chap. 3). For the purpose of undertaking and recording a clinical tooth wear examination, quantitative assessments using numerically based clinical indices with scoring based on agreed clinical descriptions may offer improved intra- and inter-assessor agreement and greater reliability with the evaluation of disease progression. An index may also help plan treatment need. However, the universal agreement of a tooth wear index in general dental practice, is lacking. The TWI (Tooth Wear Index) [18], the Basic Erosive Wear Examination (BEWE) [19], and the Tooth Wear Evaluation System (TWES) [20], are some of the betterknown clinical tooth wear indices. However, a study of practitioner habits, has reported the routine use of a clinical tooth wear index amongst only 13.5% of the participants [21]. The established aetiological factors for tooth wear have also been used to classify the type of wear present. However, as the pathogenesis of tooth wear is frequently multi-factorial, where further co-factors (which are not directly responsible for the pathology observed) may also be involved, the practical application of a classification using specific aetiological factors may prove highly challenging. Nevertheless,

108

B. Loomans and S. Mehta

as erosive factors have been reported to be commonly involved [22], the use of the term, “erosive tooth wear” is sometimes used synonymously with the overall condition of tooth wear, especially within the European literature. Using cluster analysis, some clinical features have been described to categorise patients with signs of tooth wear with either, a chemical aetiology, a mechanical etiology, or a combination of the two [23, 24]. Accordingly, the nature of the presenting wear may be broadly divided into mechanical wear or chemical wear, with four sub-types, hence: • mechanical intrinsic tooth wear (also termed attrition, due to chewing or bruxism—grinding/clenching) • mechanical extrinsic tooth wear (abrasive tooth wear, due to factors other than chewing and/or bruxism) • chemical intrinsic tooth wear (erosion, as consequence of gastric acid) • chemical extrinsic tooth wear (erosion, from the effect of an acidic diet) The erosive component may also have a ‘multiplier effect,’ where chemical exposure or mechanical wear in isolation will result in less tooth wear than when the effects of the factors are combined. Examples of these sub-types can be seen in Figs. 9.2 and 9.3.

9.3

Counselling and Monitoring

When pathological wear is diagnosed or suspected, the patient’s history of complaint must include an appraisal of the presence/or absence of any concerns relating to; impaired oro-facial aesthetics, pain and sensitivity, functional challenges (with effective mastication and phonetics), a past dental history of deteriorating dental hard tissues and restorations, and/or any anxiety about the status, integrity, and

Fig. 9.2  An example of mechanical extrinsic tooth wear, with the main aetiological factor being grinding and clenching

9  A Pragmatic Philosophy of Tooth Wear Management

109

Fig. 9.3  An example of chemical intrinsic tooth wear, related to gastro-oesophageal reflux disease (GORD)

longevity of their dentition. The patient’s medical, dental and socio-behavioral history must also be carefully reviewed, which may also help to identify risk factors for tooth wear, such as, a diagnosis of reflux or certain dietary habits. Where indicated, the patient’s oral health related quality of life (OHRQoL) can also be assessed by using a questionnaire comprising statements to determine the impact of oral health or disease on their daily functioning, well-being and their overall quality of life [25]. Multiple versions of the original OHIP (Oral Health Impact Profile) comprising 49 statements (OHIP-49) have been described, including a recently a modified version consisting of 26 statements, in which the questions were focussed for the assessment of the effects of tooth wear on the oral health related quality of life [13]. Given the, complexity and costs (financial, time and sometimes, biological) and the longer-term high maintenance needs where restorative rehabilitation is prescribed for a wearing dentition [26], it would seem illogical to embark upon such forms of treatment, for instance, when the patient may have no functional concerns, dissatisfaction associated with their wearing dentition and the absence of any clear demand for restorative intervention [17]. However, having diagnosed pathology (or signs of severe wear), any necessary counselling and monitoring must be provided [16, 17]. The latter are consistently advised, irrespective of likelihood of future restorative intervention, as a restored worn dentition in the presence of uncontrolled, destructive aetiological factors may demonstrate premature failure. For each patient with moderate or severe tooth wear, without functional or aesthetically related demands, counselling and monitoring is the treatment of first choice. The process of counselling involves informing the patient of their diagnosis in a manner they can understand, creating the necessary awareness and establishing a

110

B. Loomans and S. Mehta

tailored preventive programme. Monitoring involves the objective assessment of the level of tooth wear present, and its progression with time. [16] Counselling requires the identification of the likely aetiological (risk) factors (Chap. 3), which in turn depends on careful patient history taking. [16] The preventive plan prescribed should aim to eliminate (or in the least, effectively manage) the likely aetiological factors. The patient must take responsibility for the prevention of their tooth wear and the risks of failing to do so, must be clearly emphasised. Refraining from habits such as poor oral hygiene care at home, pencil biting, continual pipe smoking or holding hairpins may help with the management of mechanical extrinsic tooth wear. Mechanical intrinsic tooth wear may result from a tendency towards bruxism. The latter may be subdivided into awake bruxism (associated with jaw clenching) or nocturnal bruxism (associated with a tooth grinding and clenching habit) (Chap. 7) [27]. Psychological stress and anxiety have been associated with the former variety of bruxism, whilst the latter is now classified as a sleep-related movement disorder. Stress management may therefore be appropriate for some patients. Splint therapy (Chap. 11) with full coverage appliances may be advised for patients diagnosed with bruxism [27–29]. A variety of splints may be prescribed, and these include soft splints, hard splints or hybrid splints. However, compliance with appliance wear may be inconsistent. Furthermore, the evidence to support the efficacy of occlusal splints to prevent tooth wear from bruxist tendencies, is limited [30]. Caution is also required when providing splints to patients with erosive tooth wear from gastric reflux, as acidic substances may accumulate within the splint. Where chemical extrinsic wear is suspected, further details about the patient’s daily habits should be attained by requesting them to keep clear a record of their food and beverage intake, medication usage and the use of oral healthcare products for a period of four days [31]. Although the pH values of some frequently consumed soft drinks have been well documented in the literature, the clinician should also have an awareness of the buffering capacity of the drink itself to properly understand the full erosive impact. In general, where chemical extrinsic tooth wear is suspected, patients should be counselled to: avoid the frequent consumption of acidic foods and drinks and limit the consumption of erosive beverages to mealtimes and limit the number of fruit drinks to once a day, the use of a wide bore straw positioned towards the back of the mouth may help reduce contact of the erosive substrate with their teeth, consume cooled acidic drinks, avoid swirling and retaining the beverage in their mouths and from taking small sips to complete the beverage over a prolonged period [31, 32]. Diet information sheets detailing types of foods and beverages commonly associated with a higher risk of tooth wear, may also prove beneficial and patients encouraged to consume alternatives, such as water, or milk. The importance of adopting good habits may have a paramount impact on achieving effective preventive outcomes. Several medical conditions have been associated with intrinsic erosive tooth wear, to include gastro-oesophageal reflux disease (GORD) (Chap. 5). It has also been estimated that around 65% of the population suffer with this condition at some point in their lives [33]. When a diagnosis of GORD is suspected by a dental professional, simple and practical advice may be offered [34] and referral to a medical

9  A Pragmatic Philosophy of Tooth Wear Management

111

practitioner would also be indicated. Proton pump inhibitor drugs (PPI’s) that inhibit gastric reflux are often prescribed for the pharmacological treatment for GORD. Saliva also has a key role in the prevention of tooth wear (Chap. 4). Inadequate quality and quantities of saliva are critical risk factors for tooth wear. Patients with dry mouth may require further clinical investigation, especially for more severe cases of xerostomia which may be associated with Sjogren’s syndrome, or radiation to the head and neck areas. Based on the available information, patients with signs of erosive tooth wear may also be prescribed the daily use of toothpaste and or mouth rinses containing stannous fluoride (SnF2 or SnF4) [35, 36]. Having diagnosed tooth wear and provided the necessary preventive advice, vigilant professional monitoring of the level of disease progression is required. The wearing-away of tooth tissue may be episodic, with likely periods of activity and quiescence [15]. During periodic patient recall assessments, a careful history update must be attained, as well as an assessment of the progression of the tooth wear and the patient’s compliance with the prescribed preventive plan. The baseline severity of the presenting tooth wear may be scored using a clinical index, such as the TWI, BEWE, or TWES. Such clinical indices may also be applied to serial (sequential) records of traditional gypsum study casts, 3D intra-oral scans and/or intra-oral clinical photographs to help identify the presence of progressive (or quiescent) tooth wear. These serial records may be prescribed over a period of several years and will prove very helpful in demonstrating the pattern and severity of tooth wear, help gain further insight into the likely aetiology and aid visualisation of any progression. Where the clinician is satisfied that the pattern of wear is not progressing pathologically and with no further concerns, new records may be taken at two to three yearly intervals; no further active (restorative) intervention may be necessary and the circle of monitoring as presented in Fig.  9.1 can continue. However, careful monitoring of the worn dentition should take place periodically (to include the restored dentition), and risk assessment undertaken routinely during examination appointments. The patient shown in Fig. 9.4 is an example of localised severe tooth wear affecting the palatal surfaces of their maxillary anterior teeth and a moderate level of tooth wear involving the posterior sextants. There were no functional or aesthetical demands. Based on the location of the tooth wear at the non-occluding areas and the presence of an ‘enamel-cuff’ at the cervical areas of the upper anterior teeth with the presence of ‘cuppings’ in the premolar and molar regions, a predominant chemical aetiology was suspected. As no treatment demand was present, it was decided to monitor the wear pattern. At the one and three years recall intervals, new records were made, and a digital 3D subtraction analysis was undertaken to visualise the differences between the baseline and the three year-scans. As seen in Fig. 9.4, the presence of ‘green areas’ in the analysis represents a stable situation and ‘blue areas,’ the loss of tooth material. In this case, following the prescription of an appropriate preventive plan, the progression of tooth wear was seen to be minimal over an assessment period of 3 years. Where progressive tooth wear is suspected, further investigation of the aetiology may be required, as well as consideration for a referral to a dental or medical colleague, and/or some revision of the prescribed preventive plan. In some cases, and

112

B. Loomans and S. Mehta

3.00 2.52 2.03 1.55 1.07

Baseline

Recall 3 years

3D subtraction

0.58 0.10 –0.10 –0.58 –1.07 –1.55 –2.03 –2.52 –3.00

Fig. 9.4  A 35-year-old male patient. Progression of tooth wear was monitored over a period of 3 years. Progression of tooth wear was only visible at some isolated locations (highlighted in blue) which did not result in any functional concerns. Collectively with the patient, it was decided to continue with the monitoring procedure

even after thorough investigation, the aetiological factors that may have caused the tooth wear may remain unclear and undetermined, sometimes referred to as ‘idiopathic wear.’ The patient shown in Fig. 9.5a, b presented with a severe and generalised pattern of tooth wear where a diagnosis of hyposalivation was also made. The patient had no functional or aesthetic concerns nor were they showing a commitment for any restorative intervention. It was, therefore, decided to commence care planning with counseling and monitoring. Despite the rapid progression of wear over time, they had expressed no further commitment towards any restorative intervention. However, having been presented with their successive 3D scans, they developed a greater awareness of the situation. After four years, commitment for the restorative intervention was obtained and direct composite restorations were prescribed. In a situation where the patient may not consent and/or display the level of commitment required for further restorative intervention and where the tooth wear is also of a progressive nature, the interval period for serial monitoring may be shortened. In general, active restorative intervention should be deferred for as long as reasonably practical to help delay the entry of the patient into the restorative cycle of care and the ongoing maintenance needs. Clear, complete and accurate patient records are made of any discussions (e.g. supervised neglect) that may have taken place, to include the attainment of informed consent (Chap. 8).

9.4

Restorative Intervention

Restorative intervention would be indicated when the presenting tooth wear is a clear concern for the patient and / or the clinician, where there may be functional or aesthetic concerns and / or symptoms of pain or discomfort (Fig. 9.1). Earlier

9  A Pragmatic Philosophy of Tooth Wear Management

113

Baseline

1.5 years

4 years

After treatment

Baseline

1.5 years

4 years

After treatment

Fig. 9.5 (a) A 45-year-old female patient with severe generalised tooth wear. Monitoring revealed a rapid progression of wear over a 4-year period. At the 4-year recall, she understood the worsening situation and became more aware of the problem. Commitment for restorative intervention was obtained and treatment was provided using direct composite resin restorations. (b) Intra-oral photographs showing the time-line from initial presentation, through monitoring to completion of restorative treatment with direct composite resin restorations

intervention may also be appropriate where further delay with restorative rehabilitation may render the technical execution of the treatment challenging (e.g. where continued loss of dental hard tissues could significantly undermine the ability to effectively support and retain a dental restoration) and/or make the risk of endodontic complications more likely [17, 37]. The decision to commence restorative treatment must be made jointly between the clinician and patient, a process often referred to as ‘shared decision making.’ However, definitive dental restorations for tooth wear management should not be prescribed until full patient commitment can be secured. The temptation to undertake complex rehabilitation of a minimally worn dentition, or to rush into such forms of treatment must be avoided [17]. Some delay during the monitoring period will offer the dental professional the opportunity to assess the patient’s commitment, their expectations, the dentistpatient relationship and their overall understanding of the proposed restorative treatment plan.

114

B. Loomans and S. Mehta

A plethora of clinical techniques and dental materials have been described for the restorative rehabilitation of tooth wear, ranging from direct to indirect protocols, and the use of metallic and non-metallic dental materials [14, 37, 38]. As per the European Consensus Statement on the Management Guidelines (for Severe Wear) [17], restorative treatment should ideally be conservative and of an ‘additive’ nature, rather than ‘subtractive’, thereby reducing the need for the further loss of healthy tooth tissue and the higher risks of unwanted pulp tissue pathology (commonly associated with conventional, mechanically retained restorations). This approach may also offer the scope for contingency planning, where conventional restorations could be prescribed at a future point in time, with the patient having accepted (and ‘test-driven’) their new functional and aesthetic prescription, achieved using adhesively retained, minimal intervention techniques [14]. The use of additive techniques using dental materials such as composite resin may also permit the ease of modification, whereby further restorative material may be added or removed intra-­ orally to meet the patient’s aesthetic expectations and functional needs. [38] However, conventional prosthodontic protocols must not be excluded from treatment planning discussions for the initial round of restorative rehabilitation (Chaps. 15 and 16). Amongst patients displaying signs of severe occlusal wear, there may also be a concomitant reduction in the OVD, as a result of the lowering of the level of the occlusal surfaces of both the maxillary and mandibular teeth and insufficient dento-­ alveolar compensation. For such cases, restorative treatment is likely to require an increase in the OVD, to provide the necessary intra-occlusal space to accommodate the proposed dental restorations and provide an improvement of the aesthetic zone. Abduo and Lyons, in 2012 [39], have suggested that a minimal increase in the OVD should be applied when planning restorative rehabilitation, however, an increase of up to 5  mm may be justified. Although some patients may report post-operative signs and symptoms as a result of this form of restorative care being provided, the effects are often transient. Where possible, the planned increase in the OVD should be established using fixed restorations. The latter offer the scope for greater predictability, as adaptation may be a lesser challenge than with the use of removable appliances [39]. The use of minimally invasive techniques is also advised where possible [37]. However, for patients with a diagnosis of temporomandibular joint dysfunction, a removable appliance should be used to plan an increase in the OVD which can also be used for the management of this condition prior to prescribing treatments that may be of an irreversible nature [39]. In Fig. 9.6, a flowchart is presented that can be applied to help determine the new OVD. The first step is to determine the location and degree of the tooth wear, hence, the presence of either generalised or localised tooth wear. Appropriately mounted gypsum study casts or digital 3D scans may be used to help estimate the increase in the OVD. Key considerations when planning the new OVD to assist in reconstructing the original size and length of the teeth include the necessity and scope to lengthen the anterior teeth, the need to provide an adequate volume/bulk of restorative material to ensure the strength of the restorations and the provision of adequate vertical occlusal support in the anterior and posterior areas

9  A Pragmatic Philosophy of Tooth Wear Management

115

Location and degree of wear Localised

Generalised

adjustment necessary

Determining the new OVD: - Estimate the loss of tooth tissue from the most worn teeth based on the original form - Is it necessary and possible to lengthen the anterior teeth? - Try to obtain sufficient bulk of restorative material yes

yes

Any complicating factors present? no no

Possible complicating factors: - Overjet (Angle Class II Division 1) - End-to-end anterior relationship - Other...

Make stops in articulator in desired OVD

Clinical try-in session: - Mock-up maxillary anterior teeth with direct composite restorations - Check smile-line (lip generated smile design) - Obtain informed consent from patient

approve

Determination of new OVD

Fig. 9.6  Flow chart: determining the new OVD

Fig. 9.7  Determining the new OVD using mounted study casts and making silicone occlusal stops to transfer the new OVD to the clinical setting

[16]. The condition of the most worn tooth/teeth will also be a leading factor. There may, however, also be other challenges that require further thought, such as, the presence of an anterior open bite, an edge-to-edge incisor relationship, or an Angle’s Class II Division 1 occlusal relationship. In the latter case, an increase in the OVD may make it impossible to achieve anterior occlusal contact. Under such circumstances, the treatment plan may require some amendment, for instance, to include a smaller increase in the OVD than initially planned, or the need for a multidisciplinary approach such as orthodontic treatment planning to help achieve a predictable end result. For cases of localised tooth wear where the placement of restorations in the supra-occlusal position is planned, careful consideration must also be given to the eruptive potential and the patient’s oral health, which may contraindicate this approach [38]. As seen in Fig. 9.7, and in order to help determine an appropriate functional and aesthetic restorative prescription, the estimated OVD from a set of appropriately mounted study casts may be recorded by fabricating a pair of (bilateral) silicone occlusal records prepared in the premolar areas and transferred to the clinical setting. Once set, the silicone occlusal stops are trimmed with a scalpel to allow free lateral and protrusive mandibular movements while maintaining the new OVD [16,

116

B. Loomans and S. Mehta

40]. Then, by using the concepts and practical techniques applied when undertaking rehabilitation of tooth wear involving the aesthetic zone (to include digital smile design) [41], in this case the ‘lip-generated smile design’ concept described by Morley and Eubank 2001 [42], with the silicone bite blocks in situ, an intra-oral mock-up involving the direct application of un-bonded composite resin to the maxillary anterior teeth to determine an appropriate aesthetic prescription, is carried out. After attaining approval of the proposed colour and shape of the restorations by the patient, the mock-up should be recorded photographically or by the means of an intra-oral scan. The mock-up and silicone occlusal stops are subsequently removed. An impression of the mock-up in situ may also provide further information to guide the design and placement of the definitive restorations, to include the fabrication of a diagnostic wax-up. If the estimated increase in OVD in combination with the mock-up produces the desired result, these occlusal stops may also be used during the definitive restorative phase as a guide to transfer the new OVD to the mouth in a controlled manner.

9.5

The Outcomes of Restorative Intervention

The outcomes of restorative intervention may be evaluated by considering the survival or success of the treatment intervention and the impact of the treatment on the patient’s quality of life. The primary aim of restorative treatment for a more severely worn dentition is to obtain and preserve a good quality of life for the patient. A 2016 systematic review of the materials and techniques used for the restoration of the severely worn dentition reported annual failure rates of, 0.4% (micro-hybrid) to 26.3% (micro-filled) direct resin composite restorations, 0% to 14.9% for indirect resin composite restorations and, 2.7% for porcelain veneers [43]. There was no clear reason for the preference of any of these materials or techniques for the rehabilitation of the severely worn dentition. An earlier systematic review of the treatment options for managing tooth wear in 2014 was unable to provide strong evidence to support the prescription of composite resin over glass ceramic materials for the final restoration of tooth wear, however, the need for a protective mouthguard and regular follow-up were indicated [44]. Patient Related Outcome Measures (PROMS) may be used to assess the quality of care delivered from the patient’s perspective. Specific aspects, such as chewing ability, orofacial appearance, speech, and oral health impact profile have more recently been investigated. One study in 2018 reported a significant improvement in the OHRQoL and orofacial appearance amongst a group of patients with moderate to severe tooth wear where there had been a request for restorative treatment and where full mouth rehabilitation was provided using resin composite restorations [11]. A subsequent study in 2020 also reported an improvement in the self-­perception of the quality of speech amongst tooth wear patients following occlusal rehabilitation [45]. Whilst restorative treatment of generalised tooth wear using direct composite resin restorations was not observed to have a significant short-term effect on

9  A Pragmatic Philosophy of Tooth Wear Management

117

masticatory performance, the self-reported improvement in the ability to eat and chew post-treatment using the OHIP-49 questionnaire was significant [46]. In general, and as part of the process of attaining informed consent, it is important to discuss the risks, the benefits, the reasonable alternative options, the cost and likely prognosis of the proposed treatment, what may happen if the proposed treatment is not provided and the longer-term care requirements. Clear, contemporaneous, complete, and accurate clinical records must be made and maintained [47].

9.6

Conclusion

The management of a patient with tooth wear would usually commence with a comprehensive assessment and an exploration of relevant aetiological factors. Based on this information, appropriate preventive measures should be advised. For cases of moderate to severe tooth wear without any functional problems or aesthetic demands, care should always start with counselling and monitoring. When restorative intervention is necessary as outlined in subsequent chapters, minimally invasive and adhesive restorative strategies are preferred.

References 1. Bartlett D, Dugmore C. Pathological or physiological erosion--is there a relationship to age? Clin Oral Investig. 2008;12(Suppl. 1):S27–31. https://doi.org/10.1007/s00784-­007-­0177-­1. 2. Burke FM, McKenna G.  Toothwear and the older patient. Dent Update. 2011;38(3):165–8. https://doi.org/10.12968/denu.2011.38.3.165. 3. Lambrechts P, Braem M, Vuylsteke-Wauters M, Vanherle G. Quantitative in vivo wear of human enamel. J Dent Res. 1989;68(12):1752–4. https://doi.org/10.1177/00220345890680120601. 4. Van't Spijker A, Rodriguez JM, Kreulen CM, Bronkhorst EM, Bartlett DW, Creugers NH. Prevalence of tooth wear in adults. Int J Prosthodont. 2009;22(1):35–42. 5. Kelleher M, Bishop K. Tooth surface loss: an overview tooth surface loss. In: Ibbetson R, Eder A, editors. BDJ books; 2000. p. 1–8. Ch1. 6. Bartlett DW, Lussi A, West NX, Bouchard P, Sanz M, Bourgeois D. Prevalence of tooth wear on buccal and lingual surfaces and possible risk factors in young European adults. J Dent. 2013;41(11):1007–13. https://doi.org/10.1016/j.jdent.2013.08.018. 7. Schlueter N, Luka B. Erosive tooth wear - a review on global prevalence and on its prevalence in risk groups. Br Dent J. 2018;224(5):364–70. https://doi.org/10.1038/sj.bdj.2018.167. 8. Wazani BE, Dodd MN, Milosevic A. The signs and symptoms of tooth wear in a referred group of patients. Br Dent J. 2012;213(6):E10. https://doi.org/10.1038/sj.bdj.2012.840. 9. Papagianni CE, van der Meulen MJ, Naeije M, Lobbezoo F.  Oral health-related quality of life in patients with tooth wear. J Oral Rehabil. 2013;40(3):185–90. https://doi.org/10.1111/ joor.12025. 10. Li MHM, Bernabé E. Tooth wear and quality of life among adults in the United Kingdom. J Dent. 2016;55:48–53. https://doi.org/10.1016/j.jdent.2016.09.013. 11. Sterenborg BAMM, Bronkhorst EM, Wetselaar P, Lobbezoo F, Loomans BAC, Huysmans MDNJM. The influence of management of tooth wear on oral health-related quality of life. Clin Oral Investig. 2018;22(7):2567–73. https://doi.org/10.1007/s00784-­018-­2355-­8. 12. Daly B, Newton T, Fares J, Chiu K, Ahmad N, Shirodaria S, Bartlett D. Dental tooth surface loss and quality of life in university students. Prim Dent Care. 2011;18:31–5.

118

B. Loomans and S. Mehta

13. Mehta SB, Loomans BAC, Banerji S, Bronkhorst EM, Bartlett D. An investigation into the impact of tooth wear on the oral health related quality of life amongst adult dental patients in the United Kingdom, Malta and Australia [published online ahead of print, 2020 Jun 10]. J Dent. 2020;103409 https://doi.org/10.1016/j.jdent.2020.103409. 14. Mehta SB, Banerji S, Millar BJ, Suarez-Feito JM. Current concepts on the management of tooth wear: Part 3. Active restorative care 2: the management of generalised tooth wear. Br Dent J. 2012;212(3):121–7. Published 2012 Feb 10. https://doi.org/10.1038/sj.bdj.2012.97. 15. Bartlett D.  A personal perspective and update on erosive tooth wear—10 years on: Part 1—Diagnosis and prevention. Br Dent J. 2016;221(3):115–9. https://doi.org/10.1038/ sj.bdj.2016.555. 16. Loomans B, Opdam N. A guide to managing tooth wear: the Radboud philosophy. Br Dent J. 2018;224(5):348–56. https://doi.org/10.1038/sj.bdj.2018.164. 17. Loomans B, Opdam N, Attin T, Bartlett D, Edelhoff D, Frankenberger R, Benic G, Ramseyer S, Wetselaar P, Sterenborg B, Hickel R, Pallesen U, Mehta S, Banerji S, Lussi A, Wilson N. Severe tooth wear: European Consensus Statement on Management Guidelines. J Adhes Dent. 2017;19(2):111–9. https://doi.org/10.3290/j.jad.a38102. 18. Smith BG, Knight JK. An index for measuring the wear of teeth. Br Dent J. 1984;156(12):435–8. https://doi.org/10.1038/sj.bdj.4805394. 19. Bartlett D, Ganss C, Lussi A. Basic Erosive Wear Examination (BEWE): a new scoring system for scientific and clinical needs. Clin Oral Investig 2008; 12 (Suppl. 1): S65-S68. doi: https:// doi.org/10.1007/s00784-­007-­0181-­5. 20. Wetselaar P, Wetselaar-Glas MJM, Katzer LD, Ahlers MO. Diagnosing tooth wear, a new taxonomy based on the revised version of the Tooth Wear Evaluation System (TWES 2.0). J Oral Rehabil. 2020;47(6):703–12. https://doi.org/10.1111/joor.12972. 21. Mehta SB, Loomans BAC, Bronkhorst EM, Banerji S, Bartlett D.  A study to investigate habits with tooth wear assessments among UK and non-UK dental practitioners. Br Dent J. 2020;228(6):429–34. https://doi.org/10.1038/s41415-­020-­1326-­z. 22. Carvalho TS, Colon P, Ganss C, et  al. Consensus report of the European Federation of Conservative Dentistry: erosive tooth wear—diagnosis and management. Swiss Dent J. 2016;126(4):342–6. 23. Hammoudi W, Trulsson M, Smedberg JI, Svensson P. Clinical presentation of two phenotypes of tooth wear patients. J Dent. 2019;86:60–8. https://doi.org/10.1016/J.dent.2019.05.028. 24. Hammoudi W, Trulsson M, Smedberg JI, Svensson P.  Phenotypes of patients with extensive tooth wear: a novel approach using cluster analysis. J Dent. 2019;82:22–9. https://doi. org/10.1016/j.jdent.2019.01.001. 25. Locker D, Slade G.  Oral health and the quality of life among older adults: the oral health impact profile. J Can Dent Assoc. 1993;59(10):830–3. 837-8, 844 26. O'Toole S, Pennington M, Varma S, Bartlett DW. The treatment need and associated cost of erosive tooth wear rehabilitation—a service evaluation within an NHS dental hospital. Br Dent J. 2018;224(12):957–61. https://doi.org/10.1038/sj.bdj.2018.444. 27. Rees JS, Somi S. A guide to the clinical management of attrition. Br Dent J. 2018;224(5):319–23. https://doi.org/10.1038/sj.bdj.2018.169. 28. Mehta SB, Banerji S, Millar BJ, Suarez-Feito JM. Current concepts on the management of tooth wear: Part 1. Assessment, treatment planning and strategies for the prevention and the passive management of tooth wear. Br Dent J. 2012;212(1):17–27. Published 2012 Jan 13. https://doi.org/10.1038/sj.bdj.2011.1099. 29. Delivering better oral health: an evidence-based toolkit for prevention. Third edition, March 2017: https://www.gov.uk/government/publications/delivering-­better-­oral-­health-­an-­ evidence-­based-­toolkit-­for-­prevention 30. Johansson A, Omar R, Carlsson G.  Bruxism and prosthetic treatment: a critical review. J Prosthodont Res. 2011;55:127–36. 31. Carvalho JC, Scaramucci T, Aimée NR, Mestrinho HD, Hara AT. Early diagnosis and daily practice management of erosive tooth wear lesions. Br Dent J. 2018;224(5):311–8. https://doi. org/10.1038/sj.bdj.2018.172.

9  A Pragmatic Philosophy of Tooth Wear Management

119

32. Buzalaf MAR, Magalhães AC, Rios D. Prevention of erosive tooth wear: targeting nutritional and patient-related risks factors. Br Dent J. 2018;224(5):371–8. https://doi.org/10.1038/ sj.bdj.2018.173. 33. Dent J, El-Serag HB, Wallander MA, Johansson S. Epidemiology of gastro-oesophageal reflux disease: a systematic review. Gut. 2005;54(5):710–7. https://doi.org/10.1136/gut.2004.051821. 34. Moazzez R, Austin R.  Medical conditions and erosive tooth wear. Br Dent J. 2018;224(5):326–32. https://doi.org/10.1038/sj.bdj.2018.166. 35. Lussi A, Buzalaf MAR, Duangthip D, Anttonen V, Ganss C, João-Souza SH, Baumann T, Carvalho TS. The use of fluoride for the prevention of dental erosion and erosive tooth wear in children and adolescents. Eur Arch Paediatr Dent. 2019;20(6):517–27. https://doi.org/10.1007/ s40368-­019-­00420-­0. Epub 2019 Feb 14 36. Schlueter N, Klimek J, Ganss C.  Effect of stannous and fluoride concentration in a mouth rinse on erosive tissue loss in enamel in vitro. Arch Oral Biol. 2009;54(5):432–6. https://doi. org/10.1016/j.archoralbio.2009.01.019. Epub 2009 Mar 10 37. Mehta SB, Banerji S, Millar BJ, Suarez-Feito JM. Current concepts on the management of tooth wear: Part 2. Active restorative care 1: the management of localised tooth wear. Br Dent J. 2012;212(2):73–82. https://doi.org/10.1038/sj.bdj.2012.48. 38. Mehta SB, Banerji S, Millar BJ, Suarez-Feito JM. Current concepts on the management of tooth wear: Part 4. An overview of the restorative techniques and dental materials commonly applied for the management of tooth wear. Br Dent J. 2012;212(4):169–77. Published 2012 Feb 24. https://doi.org/10.1038/sj.bdj.2012.137. 39. Abduo J, Lyons K. Clinical considerations for increasing occlusal vertical dimension: a review. Aust Dent J. 2012;57(1):2–10. https://doi.org/10.1111/j.1834-­7819.2011.01640.x. 40. Hamburger J, Opdam N, Loomans B. Direct posterior esthetics: a management protocol for the treatment of severe tooth wear with resin composite (Chapter 6); Direct posterior esthetics: clinical case (Chapter 7). In: Banerjee, editor. Minimally invasive esthetics: essentials in esthetic dentistry. Amsterdam: Elsevier Health Sciences; 2015. 41. Mehta SB, Banerji S. The restorative management of tooth wear involving the aesthetic zone. Br Dent J. 2018;224(5):333–41. https://doi.org/10.1038/sj.bdj.2018.174. Epub 2018 Mar 2 42. Morley J, Eubank J.  Macroesthetic elements of smile design. J Am Dent Assoc. 2001;132(1):39–45. https://doi.org/10.14219/jada.archive.2001.0023. 43. Mesko ME, Sarkis-Onofre R, Cenci MS, Opdam NJ, Loomans B, Pereira-Cenci T. Rehabilitation of severely worn teeth: a systematic review. J Dent. 2016;48:9–15. https:// doi.org/10.1016/j.jdent.2016.03.003. 44. Muts EJ, van Pelt H, Edelhoff D, Krejci I, Cune M. Tooth wear: a systematic review of treatment options. J Prosthet Dent. 2014;112(4):752–9. https://doi.org/10.1016/j.prosdent.2014.01.018. Epub 2014 Apr 12 45. Sterenborg BAMM, Kalaykova SI, Knuijt S, Loomans BAC, Huysmans MDNJM.  Speech changes in patients with a full rehabilitation for severe tooth wear, a first evaluation study. Clin Oral Investig. 2020;24(9):3061–7. https://doi.org/10.1007/s00784-­019-­03174-­7. Epub 2019 Dec 19; PMID: 31858244 46. Kalaykova SI, Sterenborg BAMM, Loomans BAC, Huysmans MDNJM. Impact of restorative treatment of tooth wear upon masticatory performance. J Dent. 2019;88:103159. https://doi. org/10.1016/j.jdent.2019.06.006. Epub 2019 Jun 24. PMID: 31247283 47. Standards for the Dental Team. General Dental Council, UK September 2013.: https://standards.gdc-­uk.org/

Treatment Planning for Patients with Tooth Wear

10

Robert Stone

10.1 Introduction Treatment planning is the synthesis of the information gathering process, clinical diagnosis, and reflection on a patient’s needs, wishes and expectations. Unfortunately, this process is not always linear with respect to restorative dentistry. Diagnoses can be multiple and may require irreversible investigative processes to achieve diagnostic confirmation and reassessment of treatment planning. To achieve comprehensive treatment planning a clinician should provide: 1. A modern comprehensive diagnostic evaluation 2. Prevention and stabilisation of primary disease processes 3. Protection and restoration of tooth structure and function 4. Maintenance and review

10.2 P  atient History: A Guide to Diagnosis and a Tool for Assessing Risk Identifying the patient’s chief complaint, perceived desires and preferred outcomes at the outset is essential although aspects may change as the information gathering and diagnostic processes progress. For example, patients may be unaware of the full extent of their tooth wear at initial presentation. The European Consensus Statement on Managing Severe Tooth Wear [1] recommends ‘the OHIP-49 questionnaire to test the Oral Health Related Quality of Life of patients with severe tooth wear’. The paper goes on to suggest that even with the R. Stone (*) UCL Eastman Dental Institute and Private Practice, London, UK e-mail: [email protected] © Springer Nature Switzerland AG 2022 A. Eder, M. Faigenblum (eds.), Tooth Wear, BDJ Clinician’s Guides, https://doi.org/10.1007/978-3-030-86110-0_10

121

122

R. Stone

most thorough investigatory and examination processes, the multifactorial nature of tooth wear often prevents a clear diagnosis of the aetiological factors. However, an experienced clinician should be able to consider the relative weighting of each individual process. Furthermore, the ability to negate long established contributory factors may be limited; examples include night and day bruxism, bulimia and chronic gastro-oesophageal reflux disease. That said, steps can be taken to minimise their effects from both a preventive and a therapeutic stance. In parallel, a comprehensive medical history, dental history and social history should be investigated and recorded as follows: • A medical history should be taken to prevent complications and guide a holistic approach, before, during and after dental treatment. • The dental history should include the restorative, endodontic, orthodontic, periodontal, soft tissue, craniofacial and trauma histories. • The social history should include occupation, lifestyle, diet and oral hygiene regimes past and present. When all is considered together, this information will not only assist the clinician in determining the primary source of tooth wear but may also have implications on the future management, treatment decision making and ultimately the predictability and longevity of any treatment outcomes.

10.3 Examination and Records 10.3.1 Extra-Oral Examination The extra-oral examination should include analysis of the temporomandibular joints (TMJs) and associated musculature. Pain, clicking, crepitus, deviation and range of movement should be assessed. The TMJs should be palpated, laterally and posteriorly, for pain and tenderness. Palpation should also be used to assess the muscles of mastication (masseter, temporalis, occipitalis, medial pterygoid, sternocleidomastoid and suprahyoid). This is also a convenient time to palpate the submandibular and cervical lymph nodes along with the parotid for enlargement and tenderness. Parotid tenderness is often seen in patient’s suffering from bulimia [2]. Additional analysis of the craniofacial, facial, dento-labial soft tissues and phonetics are important parameters when considering tooth wear. Good photography and even video skills are essential to augment and record many of these aspects. Tooth wear often has a significant aesthetic component. The lips, gingival and ‘incisal show’ should be noted and recorded both at rest and when smiling broadly. The vertical dimension can be recorded at rest and in maximum intercuspation. This will enable an assessment of the degree of dento-alveolar compensation and have significant implications on space requirements.

10  Treatment Planning for Patients with Tooth Wear

123

10.3.2 Intra-Oral Examination The intra-oral examination should assess soft tissue health and the presence of any pathology and also record indicators of tooth wear associated parafunction. Examples include linea alba and tongue scalloping. The endodontic status, remaining tooth structure, periodontal status and orthodontic requirements should all be analysed, with the assistance of appropriate radiographs where necessary. Lastly, a detailed occlusal evaluation is performed, recorded and reproduced in the form of accurate mounted study casts that capture the mandible closing on the hinge axis. Once again, high quality intra-oral photography is vital. At the end of this comprehensive information gathering process, the clinician should have the best possible representation of the patient without the patient actually being present in the surgery. The process of care planning can then begin with time and space to think clearly; starting on a tooth-by-tooth basis and then expanding to consider groups of teeth, their strategic importance, the availability of anterior guidance and posterior stability before moving to consider both arches as one stomatognathic system. An invaluable tool in this analysis is the production of accurate study casts (Figs.  10.1 and 10.2) mounted on a semi-adjustable articulator. Impressions taken using rigid, preferably metal, trays with alginate or an elastomeric material if they cannot be poured in good time. The casts should be mounted on the hinge axis with the aid of a face-bow record and using a tooth apart inter-occlusal record using a Lucia jig, bimandibular manipulation and a rigid wax carrier. The mounted study casts should be verified and checked against the clinical findings but caution should be exercised as the mouth is far better at hiding fine occlusal contacts than an articulator. An endodontic evaluation should record the vitality of the teeth using a cold test in conjunction with an electronic pulp tester. If negative, this can then be followed up with a long cone periapical radiograph that can be used to evaluate the periradicular structures and the presence of pathology. Loss of vitality due to tooth wear is relatively uncommon (0.96%) [3]. Tooth wear is, usually, a slow process that Fig. 10.1  Centric jaw relationship record (bimandibular manipulation)

124

R. Stone

Fig. 10.2  Facebow record, Lucia jig, centric relation record and maxillary and mandibular alginate impressions in metal Rimlock trays

allows the pulpal tissues to adapt and lay down tertiary dentine. Baseline bitewing radiographs give an indication of bone levels, caries, pulpal changes, restorative margins and the availability of proximal enamel. Tooth structure evaluation can be difficult at times, especially when extra coronal restorations have been placed; old working dies or digital impressions are helpful but seldom present. Ultimately, the only solution is to investigate the tooth by removing the existing extra-coronal or large intra-coronal restorations and assessing the remaining tooth structure. This can be problematic and is often one of the most difficult treatment planning concerns for a dental practitioner. The investigation commits the clinician to irreversible intervention and the findings could drastically alter the working treatment plan. If this is the case, the patient needs to be fully informed of the possible outcomes and consent to the investigation. Having investigated the tooth, how much tooth structure is actually required? This is a complex question and rather depends on the desired treatment modality. If the clinical approach is developing along conventional lines; clinical crown height and remaining dentine are critical. For example, if 2–4 mm of crown height remains there may be options to augment the core with a composite or amalgam albeit dependent on the availability and positioning of tooth structure to providing resistance form. Tooth structure is required to provide protection for a post and core restoration. A 2 mm collar, known as a ferrule, confluent with the margin is an essential prerequisite for success [4]. However, if the crown height is less than 3 mm one must attempt to increase the height by crown lengthening or orthodontic extrusion (Chaps. 13 and 14).

10  Treatment Planning for Patients with Tooth Wear

125

Over the last 20 years, there has been a paradigm shift in the management of tooth wear. Adhesive management has been embraced (Chap. 15). Adhesive restorative treatment allows for an additive rather than a subtractive approach. This makes perfect sense as the concept of removing more tooth structure to restore already heavily damaged teeth is surely flawed. When employing an adhesive approach, the presence of circumferential enamel, sometimes referred to as the ‘tennis racket effect’ is preferred to crown height, resistance form and ferrule. Isolation, cleaning and specific bonding protocols are essential for success. There is even possibility of raising a sub-gingival margin in a small section to provide supragingival isolation and an accessible margin for further bonding; this has been described as deep margin elevation [5]. An orthodontic evaluation is an invaluable adjunct to conservative treatment of tooth wear (Chap. 14). The ability to create inter-occlusal space, align teeth and their gingival margins are vital considerations in planning for functional and aesthetic integration. A multidisciplinary approach is often essential, with input from all clinical disciplines at the earliest possible opportunity, to plan for the best possible outcomes with particular attention being given to determining the critical occlusal requirements (Fig. 10.3a–d). A full periodontal examination should be carried out. Six-point pocket charting, plaque and bleeding indices will give the clinician the most thorough clinical picture. Attachment levels, furcation involvement and mobility should also be recorded although it must be noted that chronic periodontal disease and generalised tooth wear are rarely seen together. Where short clinical crown height is a particular issue, crown lengthening might be a viable adjunct to facilitate care (Chap. 13).

a

b

c

d

Fig. 10.3 (a) Incisal tooth wear and uneven gingival margins. (b) Orthodontic treatment to align teeth and gingival margins. (c) Post-orthodontic treatment with balanced gingival margins. (d) Tooth wear restored with direct composite resin

126

R. Stone

The occlusal evaluation should be the synthesis of the information gained from the clinical examination and analysis of the mounted casts (Chap. 11). With time and experience, analysis of the mounted casts will be an essential addition to the clinical examination as the soft tissues and neuromuscular condition often hinder the ability to visualise and record occlusal contacts clinically. The analysis should include static inter-cuspal holding contacts, the presence of posterior stability, the nature and availability of anterior guidance, dynamic contacts in protrusion and lateral excursions including both working and non-working contacts. The first point of contact in the retruded position, the presence and the nature and size of any slide observed. Finally, the curves of Spee and Monson should be assessed along with any disturbances in the occlusal plane. You will also be able to evaluate more accurately the nature of parafunctional activity and pattern of attrition. Mounted study casts in conjunction with the relevant photographic images are essential for planning the space requirements which are normally critical to the management of most tooth wear cases. Turner and Missirlian [6] considered three categories of generalised tooth wear patients (Table 10.1). Patients who fall into category 1, can be treated by re-establishing the original occlusal vertical dimension. The loss of occlusal vertical dimension is most usually because of rapid loss of tooth structure. Those in category 2 and 3, however, are less clear cut as a slower progressive loss of tooth structure results in dento-alveolar compensation and maintenance of the occlusal vertical dimension. For these patients, space is only available by increasing the occlusal vertical dimension. Space is rarely available and a working knowledge of the methods available, and how they may be combined, to create space is critical and outlined below: 1. Altering the position of mandibular closure (Chap. 11): if a slide is present a clinician can alter the mandibular position by performing an occlusal equilibration to make the retruded position coincident with the inter-cuspal position. This will maintain the existing occlusal vertical dimension and will usually create a small volume of anterior space by eliminating the slide between the retruded and inter-cuspal positions. The process should be investigated and rehearsed on articulated casts to assess the biological cost and practicality of transferring this to the dentition. 2. Surgical crown lengthening (Chap. 13): can be very effective in facilitating more traditional tooth preparation techniques that rely on retention and resistance form. The ability to simultaneously balance the gingival architecture is also very appealing. Table 10.1  Turner classification: categories of generalised tooth wear patients Turner classification: Category 1: excessive tooth wear with loss of occlusal vertical dimension Category 2: excessive wear without loss of occlusal vertical dimension but with space available Category 3: excessive wear without loss of occlusal vertical dimension but with limited space

10  Treatment Planning for Patients with Tooth Wear

127

3. Orthodontics (Chap. 14): changing tooth position can create space but it may be difficult to provide ideal tooth-to-tooth contacts. A combination of restorative and orthodontic treatment is likely to achieve the best results in such tooth wear cases. 4. Increasing the occlusal vertical dimension (Chaps. 15 and 16): whilst this can be a helpful solution, it does mean that all teeth in at least one, or possibly both, arches will need to be restored. The amount of increase required is governed by the space requirements of the intended restorative material, to correct the aesthetic tooth display, to establish effective anterior guidance, to establish posterior stability and to avoid the need for tooth preparation, surgical crown lengthening and endodontic treatment. By analysis of the retruded position and the nature of the slide into the inter-cuspal position, it is possible to create space by restoring the worn teeth at the first point of contact. Often this first point of contact provides the perfect starting point to restore the lost tooth structure. Occasionally, it provides too little space and more vertical opening is required. However, clinicians must remember that in most Class 2 skeletal base situations, the relative anterior-posterior (horizontal) position of the incisors becomes less favourable as the vertical dimension increases. Additionally, the opening is obviously limited by the degree of vertical overlap of the anterior teeth. Both can lead to challenges in re-establishing satisfactory anterior guidance. However, there are occasions when one finds there would be too much space if the retruded position were to be adopted. In these cases, a pre-restorative occlusal adjustment is sometimes required to reduce the space available and facilitate a workable incisal relationship. Studies show that opening the vertical dimension by up to 5 mms is safe and predictable [7] with no incidences of long lasting TMJ symptoms [8]. Whilst a satisfactory solution if all teeth in one or both arches needs restoring, relative axial movement as outlined below may be more appropriate if a rather more localised approach is required for just a few teeth. 5. Tooth preparation (Chap. 16): preferable to avoid wherever possible in a patient with tooth wear but occasionally needed to facilitate occlusal adjustment, level the occlusal plane or when adhesive strategies are not an option. 6. Relative axial tooth movement (Chaps. 14, 15 and 16): this method was first described by Dahl in 1975 [9] (Fig. 10.4a–c). a

b

Dahl B, Krogstad O, Karlsen., J. Oral Rehabil, 1975: 2: 209-214

Dahl B, Krogstad O, Karlsen., J. Oral Rehabil, 1975: 2: 209-214

Fig. 10.4 (a–c) The ‘Dahl Concept’ illustrated

c

Dahl B, Krogstad O, Karlsen., J. Oral Rehabil, 1975: 2: 209-214

128

R. Stone

Dahl and co-workers used removable metal bite planes to help reduce deep traumatic overbites and restore worn anterior teeth without resorting to restoring the posterior teeth at the same time. Since the 1970’s, and in conjunction with the progress made in adhesive dentistry, the ‘Dahl Concept’ has become instrumental in the paradigm shift in how we, as clinicians, approach tooth wear cases. With careful planning to ‘axialise’ the occlusal forces generated down the long axis of the teeth in contact, we can create the space required. The space can be immediately restored with a restorative material or used in a staged approach. Planning is key and while some authors have suggested this can be planned from the intercuspal position, or even worse by ‘eye-balling’, others believe it is essential to work from the retruded position to provide the desired accuracy and to facilitate far superior control of the resulting occlusal forces. This requires a retruded relation mounting, diagnostic waxing and replication in the mouth. When planned carefully, the posterior occlusion re-establishes full arch contacts over time and dispenses with the requirement of full mouth or whole arch restorations. Modern adhesive techniques and composite material make immediate and purely additive treatment of anterior tooth wear a reality. Patient satisfaction (aesthetic and functional) is very high and although repairs will be required, they are easy to do and seldom require more complex intervention. Studies show that the thicker the composite material is used, the better the longevity [10]. All must be considered with regard to the underlying aetiology of the tooth wear, opposing tooth substance and the materials used.

10.4 Thinking Time and Space: The Planning Process Having recorded and considered all the diagnostic elements, it is important to allow time and space away from the patient to consider and reflect upon the patient, your findings and their expectations. Within this planning process, it will be essential to decide whether any further information is required, if diagnoses can be made and whether expectations are realistically deliverable. All can then be shared with the patient, normally in the form of a comprehensive report or treatment planning letter which should include the history, your findings, the diagnoses, treatment options and recommendations. Additionally, you can take this opportunity to set out the stages of treatment (Table  10.2), an appointment schedule, finances and ongoing maintenance requirements. More often than not, multiple treatment Table 10.2  Stages of treatment in the management of patients with tooth wear Stages of treatment: Stage one: Prevention and stabilisation of primary dental disease and further diagnosis Stage two: Protection and/or restoration of tooth structure, appearance and function Stage three: Maintenance and review with an emphasis on prevention

10  Treatment Planning for Patients with Tooth Wear

129

Fig. 10.5 Diagnostic wax-up determining aesthetics and function

options will be available and further explanations may be required for the patient to be able to make an informed decision and give consent for treatment to progress (Chap. 8). The prevention and stabilisation phase targets the aetiological factors, relieves pain and discomfort, ensures periodontal health, provides endodontic treatment, addresses caries and defective restorations, removes teeth that have a hopeless prognosis and makes any pre-restorative occlusal adjustments, possibly with the provision of a diagnostic occlusal splint (Chap. 11). Once the stabilisation phase has been completed, the clinician can enter the critical diagnostic phase and produce a diagnostic wax-up (Fig.  10.5). This wax-up should utilise the space available or the space created, by any one or more of the methods described above, to provide a restorative plan that fulfils the aesthetic and functional requirements of the patient. At this point, it becomes essential that this master plan (the ‘mock-up’) is tried in the mouth. This stage is essential when contemplating an adhesive approach and important but not critical if pursuing a conventional extra-coronal restorative strategy as provisional restorations can be used to elicit and refine critical information. The mock-up should be evaluated for appearance, function and phonetics (Fig.  10.6a–d). Aesthetic considerations include establishing the correct vertical centre line, incisal lip position, height-width ratios, adequate lip support and satisfactory dominance of the maxillary central incisors. Functional elements include ensuring there is sufficient vertical and horizontal overlap to provide smooth shallow to steep anterior guidance, ideally, with canine lift. Speech should be checked for comfort and particularly fricative (F and V) and ‘S’ sounds. Adjustments and refinements can be made either in the actual mock-up or in the wax-up. Multiple mock-ups may have to be used to correct different elements or try different ideas. Such examples might include whether if it is appropriate to carry out periodontal plastic surgery to reduce gingival show or obtain appropriate height-width ratios without having to lengthen the maxillary incisors beyond the lower lip resting position.

130

R. Stone

a

b

c

d

Fig. 10.6 (a) Severe maxillary anterior palatal tooth wear, caries and missing teeth. (b) Diagnostic wax-up. (c) Bis-acryl mock-up. (d) Anterior maxillary restoration with indirect composite palatal veneers on the incisors and resin bonded bridges protecting the canines and replacing the first premolars

10.5 Restorative Treatment Concepts Beyond purely preventive strategies, we have seen a dramatic change in the approach to restorative care. Previously there were good reasons to watch, monitor and wait to commence restorative care as the available treatment options were usually destructive of remaining tooth tissue and more likely to fail in an irreparable manner. There is now a strong case for much earlier intervention using additive rather subtractive techniques. Adhesion and space creation through the ‘Dahl concept’ allow for early protection of worn teeth and far easier repairs in the event of material failure—an approach described by some as being of minimal and sustainable intervention. Ultimately, this concept will hopefully free the patient from the destructive restorative cycle. First described by Elderton [11], well-illustrated by Vailati and Belser in their paper introducing the ACE Classification [12] and comprehensively updated in this book by Loomans and Mehta (Chap. 9).

10.6 Restorative Treatment Options Direct and indirect adhesive options are available and decision-making is based on the accessibility of enamel margins, aesthetic requirements, clinical skill, technical support and patient finances.

10  Treatment Planning for Patients with Tooth Wear

a

131

b

c

Fig. 10.7 (a) Gold palatal veneers restoring the maxillary anterior teeth. (b) Gold palatal veneers with buccal composite restorations. (c) Hybrid approach with composite palatal veneers on the maxillary incisors and gold palatal veneers on the maxillary canines

Composite, ceramic, gold and a plethora of hybrid materials are available. Aesthetics, wear, the nature of the opposing dentition and presenting aetiology must all be considered. Gold palatal veneers have provided beneficial protection for composite additions to lengthen anterior teeth in bruxists (Fig. 10.7a–c). Bruxists rarely stop bruxing and composite only restorations will require regular repair of fractures and chipping. Patients need to be aware of the limitations from the outset. Hard wearing materials are less critical in cases where erosion is the principal driving force for the tooth wear. In these cases, early coverage with composite materials should provide a satisfactory solution (Fig. 10.8a–d) with step-by-­ step treatment outlined (Fig. 10.9a–h). Lastly, there are occasions where a wide range of adhesive, conventional and removable options are required to re-establish appearance and function and fully care for patients with rather more significant tooth wear and missing teeth (Fig. 10.10a, b).

132

R. Stone

a

b

c

d

Fig. 10.8 (a) Buccal view showing moderate anterior tooth wear. (b) Palatal view of the worn maxillary anterior teeth. (c) Maxillary anterior teeth restored with indirect composite backings. (d) Buccal view of restored maxillary anterior teeth

a

b

c

d

e

f

g

h

Fig. 10.9 (a–h) Patient attending for anterior tooth wear management showing (a) pre-treatment, (b) diagnostic wax-up, (c) clear silicone matrix over diagnostic-wax-up, (d) clear silicone matrix with stabilisers, (e) isolation, (f) clear silicone matrix in situ, (g) direct composite restorations and (h) post-treatment

10  Treatment Planning for Patients with Tooth Wear

a

133

b

Fig. 10.10 (a) Patient with advanced tooth wear on presentation. (b) Restoration of a patient with advanced tooth wear with adhesive restorations, conventional prosthodontics and removable partial dentures—all at an increased occlusal vertical dimension

10.7 Conclusion: Maintenance and Review Patients with a history of tooth wear, whether monitored or restored, require careful and frequent review. Restored patients ultimately require multiple restorations and it is essential to remember that all restorations will only have a finite lifespan. Additionally, it is naïve to assume that all the presenting aetiological factors will have stopped and caries, periodontal disease and all or some of the primary aetiologies that drive tooth wear may still be present. However, as for all patients and their restored teeth, there is a fine balance between managing the biological and the biomechanical challenges. If we focus here on biomechanical failures, these normally occur because of excess occlusal loading. It necessarily follows that the control of the occlusion and excess loading is key to enduring restorative success. Good restoration design to axialise forces, spread load and minimise contact areas will promote longevity. To prevent early failure, additional protection with an occlusal splint (a Michigan Splint) for night wear should be strongly recommended for those patients with parafunctional habits (Chap. 11).

References 1. Loomans B, et al. Severe tooth wear: European consensus statement and management guidelines. J Adhes Dent. 2017;19:111–9. 2. Garcia BG, Ferrer AD, Jimenez ND, Granados FJA.  Bilateral parotid sialadenosis associated with long-standing Bulimia: a case report and literature review. J Maxillofac Oral Surg. 2018;17(2):117–21. 3. Rees J, Thomas M, Naik P. A prospective study of the prevalence of periapical pathology in severely worn teeth. Dent Update. 2011;38(1):24–6. 28–9 4. Hoag EP, Dwyer TG. A comparative evaluation of three post and core techniques. J Prosthet Dent. 1982;47:177–81. 5. Magne P, Spreafico RC.  Deep margin elevation: a paradigm shift. Am J Esthet Dent. 2012;2(2):86–96.

134

R. Stone

6. Turner KA, Missirlian DM.  Restoration of the extremely worn dentition. J Prothet Dent. 1984;52(4):467–74. 7. Abduo J.  Safety of increasing vertical dimension of occlusion: a systematic review. Quintessence Int. 2012;43:369–80. 8. Moreno-Hay I, Okeson JP.  Does altering the occlusal vertical dimension produce temporomandibular disorders? A literature review. J Oral Rehab. 2015;42(11):875–82. 9. Dahl BL, Krogstad O, Karlsen K. An alternative treatment in cases with advanced localised attrition. J Oral Rehab. 1975;2:209–14. 10. Gulamali AB, Hemmings KW, Tredwin CJ, Petrie A.  Survival analysis of composite Dahl restorations provided to manage localised anterior tooth wear (ten-year follow-up). Br Dent J. 2011;211(4):E9. 11. Elderton RJ. Preventative (evidence-based) approach to quality general dental care. Med Princ Pract. 2003;12(Suppl. 1):12–21. 12. Vailati F, Belser UC. Classification and treatment of the anterior maxillary dentition affected by dental erosion: the ACE classification. Int J Periodontics Restorative Dent. 2010;30(6):559–71.

Occlusion and Splint Therapy

11

Nicholas Capp and Andrew Eder

11.1 Introduction Whilst the first section of this book concentrates on the aetiology and presentation of tooth wear, this chapter focuses on occlusal consequences. Tooth wear can be considered pathological if the degree of wear exceeds the level expected at any particular age. Tooth wear affecting the functional surfaces creates difficulties for dental practitioners and may affect the stability of the occlusion. The first part of this chapter discusses the importance of occlusal stability and the possible consequences when it is lost. The second part is devoted to the role of occlusal appliances in protecting teeth from wear and some aspects of the pre-restorative management of tooth wear. The third part describes the clinical and laboratory stages of providing an occlusal splint.

11.2 The Occlusion Most functional (chewing) and parafunctional (bruxing and clenching) movements of the mandible take place around the intercuspal position (ICP). This is defined as the mandibular position in which maximum intercuspation of the teeth occurs. Functional movements result in brief contacts between maxillary and mandibular teeth, usually toward the end of the masticatory cycle. However, parafunctional activity may produce prolonged periods of forceful tooth contact. In 90% of the population, maximum intercuspation occurs slightly forward from the retruded position of the mandible to the maxilla. However, contact between N. Capp (*) Private Practice, London, UK A. Eder UCL Eastman Dental Institute and Harley Street Dental and Implant Clinic, London, UK e-mail: [email protected] © Springer Nature Switzerland AG 2022 A. Eder, M. Faigenblum (eds.), Tooth Wear, BDJ Clinician’s Guides, https://doi.org/10.1007/978-3-030-86110-0_11

135

136

N. Capp and A. Eder

opposing teeth and the resultant proprioceptive response guides the mandible repeatedly into the habitual ICP, wherever it may be. Should a patient exhibit parafunctional activity, it becomes increasingly important that there are enough opposing posterior teeth to provide stable ICP contacts, so that the forces produced during parafunction are distributed over a wide area and in the most favourable direction. Stable ICP contacts are provided by natural or restored surfaces which have appropriately steep cuspal anatomy (Fig. 11.1). Contact either between the tips of supporting cusps and opposing fossae, or three points surrounding each supporting cusp tip and the ridges surrounding the opposing fossa (tripodisation), provide stable ICP contacts which direct occlusal forces axially. They will also, in conjunction with the proximal contacts of adjacent teeth, stabilise the positions of individual teeth and also of the mandible in ICP. If ICP contacts are unstable, tilting and tipping of teeth are more likely particularly in the absence of an intact arch. This will cause further loss of stable ICP contacts and increase the likelihood of interferences occurring between the posterior teeth during lateral and protrusive movements. In order to reduce the potentially harmful lateral forces produced by bruxing on interferences between posterior teeth, it is desirable for a patient to possess adequate anterior guidance. Contact between opposing teeth, preferably the canines in lateral excursion and the central incisors in protrusion, discludes the posterior teeth as soon as the mandible moves from ICP (Fig. 11.1). This occlusal scheme most importantly reduces the number of tooth contacts occurring outside ICP. There is some evidence that this alters the proprioceptive feedback to the central nervous system which in turn reduces the level of activity in the masticatory muscles [1, 2], although this view is hard to support on scientific grounds. However, in simple practical terms, it is very much easier to make restorations in the presence of an adequately steep, immediate disclusion, provided by a small number of teeth near the front of the mouth [3].

Fig. 11.1  Restorations with adequately steep cusps provide occlusal stability in ICP while discluding the lateral and protrusive movements

11  Occlusion and Splint Therapy

137

11.3 How May Occlusal Stability Be Maintained or Lost? Most restorations are made to conform to a patient's existing ICP. For this to be an appropriate form of treatment, ICP must be stable and the occlusal anatomy of all restorations must be carefully shaped to reproduce correct contacts. In addition, the restorative materials used should be easy to manipulate to produce the necessary occlusal contacts and exhibit similar wear characteristics to enamel or to opposing restorations. This will reduce the chance of differential wear and increase the likelihood of stable contacts being maintained long-term. Gold (Fig.  11.2) and amalgam are still regarded as highly suitable restorative materials based upon these criteria. The use of composite resin (direct or indirect) or ceramic to restore large areas of multiple occlusal surfaces should be avoided in patients prone to parafunction and those with restricted anterior guidance. The difficulty in providing stable contacts and the surface hardness of these materials may result in increased tooth wear in the opposing arch (Figs. 11.3 and 11.4). The careful use of occlusal porcelain and composite resin is less harmful in individuals who possess immediate disclusion of their posterior teeth and do not parafunction. Loss of stable contacts may also occur because of tooth wear caused by acid erosion or parafunction between unrestored or similarly restored surfaces. Loss of cusp height and definition, broadening areas of ICP contact, combined with a shallowing of the anterior guidance, reduces stability and increases the chances of interferences in lateral or protrusive movements, causing increased and less favourable stress distribution in the teeth affected. Loss of occlusal stability may result in the repeated fracture of restorations and teeth, increased mobility and drifting, particularly of the upper anterior segment. Traditionally, it has also been held to potentially have other long-term effects on the structure and function of the temporomandibular joints [4, 5] although such assertions are increasingly open to question. In the presence of any of these signs of a loss of Fig. 11.2  Gold still provides the best means of restoring occlusal stability

138

N. Capp and A. Eder

Fig. 11.3  A 3-unit fixed prosthesis with inadequate occlusal form and inappropriate choice of materials for the articulating surfaces

Fig. 11.4  Tooth surface loss because of the abrasive effect of the porcelain guidance surfaces on opposing teeth

occlusal stability, it sometimes becomes necessary to reorganise the patient’s occlusion creating a new and stable ICP at the retruded position of the mandible. There is little reason to choose the retruded position other than because of ‘prosthetic convenience’. In the absence of a stable ICP, the retruded position is the only relationship of mandible to maxilla which can be repeatedly and consistently recorded and has been shown to be physiologically acceptable. It is also the maxillo-­mandibular relationship to which the mandible will return when not prevented from doing so by interfering tooth contacts. It may, therefore, be used as the reference position in which the new restorations will intercuspate when re-organising the occlusion.

11.4 The Rationale and Indications for Occlusal Splints An occlusal splint is a removable appliance covering some or all of the occlusal surfaces of the teeth in either the maxillary or mandibular arches. The ideal occlusal splint is made from laboratory-processed acrylic resin which should cover the

11  Occlusion and Splint Therapy

139

occlusal surfaces of all the teeth in one arch. It should provide even simultaneous contacts on closure on the retruded axis with all opposing teeth and anterior guidance causing immediate disclusion of the posterior teeth and splint surface outside ICP. The splint provides the patient with an ideal occlusion with posterior stability and anterior guidance. It will disrupt the habitual path of closure into ICP by separating the teeth and removing the guiding effect of the cuspal inclines. It causes an immediate and pronounced relaxation in the masticatory muscles [6], which will eventually result in the mandible repositioning and closing in the retruded position uninterfered with by the teeth. In order to achieve this muscle relaxation and mandibular repositioning, the occlusal surface of the splint is flat and without indentations so as not to hold or guide the mandible into any predetermined position. The only exception to this is the area lateral to the canine and anterior to the incisor ICP contacts which is gently ramped to provide anterior guidance. To achieve muscle relaxation and repositioning of the mandible, the splint ideally must be worn continuously, failure to do so will result in an increase in masticatory muscle activity [7, 8]. As the mandible repositions, it is necessary to adjust the splint frequently to maintain even contact and disclusion [9]. However, continuous wear may not be compatible with the patient’s daily activities. For those patients, wear at night and also if possible in the evenings will achieve the same result but more slowly.

11.5 Uses of Splints The use of an appropriate occlusal splint may be indicated in the following circumstances:

11.5.1 Prevention of Tooth Wear Patients who are prone to nocturnal bruxism should routinely wear occlusal splints at night. The splint may reduce their parafunctional activity while it is being worn but as soon as it is removed masticatory muscle activity will resume its increased levels [6]. Whether or not bruxing is continuing can be monitored by observing wear facets created on the splint surface. Even if parafunction continues the intervening splint will prevent damage to the teeth. It is important to motivate patients to wear their splints by stressing the long-term consequences of them not doing so.

11.5.2 Management of Mandibular Dysfunction Many studies have shown that an occlusal splint may be beneficial in reducing the pain experienced in mandibular dysfunction [8]. Various theories have been put forward to explain the mechanism involved. One of the more common theories is that

140

N. Capp and A. Eder

in lowering masticatory muscle activity, a splint will effectively reduce the build-up of metabolic waste products which may result in restricting muscle pain and spasm. While there is no doubt that many patients suffering from dysfunction who are treated with occlusal splints do show a significant decrease in pain levels, it is far from clear that the therapeutic effect of the splint is responsible [10]. It is possible that a significant part of this improvement is achieved through the placebo effect (although there is some evidence that occlusal treatment with a splint does have a truly therapeutic effect [11, 12]. Because of the difficulties that dentists may experience in diagnosing the source of a patient’s facial pain and the doubts which exist over the therapeutic effect of occlusal treatment, it is advisable to carry out only reversible occlusal treatment on such patients (i.e. splint therapy and not occlusal equilibration).

11.5.3 Pre-Restorative Stabilisation The first part of this chapter described the importance of occlusal stability and introduced the concept of reorganising the occlusion to create a new and stable ICP at the retruded position when stability is absent. When conforming to the existing ICP, the maxillo-mandibular relationship to which restorations are made is easily and accurately determined by the intercuspation of the teeth. When reorganising, it is necessary to locate and record the retruded position of the mandible and then mount both diagnostic and working casts on an articulator in this relationship. In the absence of stable ICP contacts, this position is determined solely by the temporomandibular joints and associated neuromuscular system. It is essential that the patient’s masticatory system is free from dysfunction, either internal derangement or extra-­capsular muscle dysfunction, in order that a correct and reproducible retruded position can be recorded. A consistent position must be recorded before embarking upon restorative treatment. If not, it is likely that changes in the occlusal relationship may occur following tooth preparation and temporisation, or cementation of the new restorations. When reorganising the occlusion it is essential to precede restorative procedures with a period of splint therapy to ensure that a stable relationship has been achieved [13].

11.5.4 Creating Space to Restore Worn Anterior Teeth Figures 11.5 and 11.6 show a patient before and after splint therapy. At initial examination (Fig. 11.5), the patient requested restoration of severely worn mandibular anterior teeth. It appeared that both ICP and the retruded position were coincident and that no space was available to correctly restore these teeth. After one month of wearing an occlusal splint (Fig.  11.6), the mandible had

11  Occlusion and Splint Therapy

141

Fig. 11.5  The intercuspal position showing contact between worn mandibular incisal edges and the opposing teeth

Fig. 11.6  One month of occlusal splint therapy resulting in posterior repositioning of the mandible

repositioned posteriorly into a stable retruded position. This created space to enable the worn teeth to be properly restored. This repositioning occurred because the pre-existing discrepancy between RCP and ICP had been hidden by the patient’s neuromuscular system.

11.5.5 Protection of New Restorations from Parafunction The aetiology of parafunction is largely stress-related. It is likely that patients will continue to brux and clench after restoration of worn teeth. It is highly advisable for them to wear a post-restorative splint to protect their new restorations from damage. This should be made clear to the patient before treatment begins.

142

N. Capp and A. Eder

11.6 T  ypes of Occlusal Splint—Advantages and Disadvantages Many types of occlusal splint have been advocated. They may be full or partial occlusal coverage, maxillary or mandibular, repositioning or stabilising, and made from a variety of different materials.

11.6.1 Choice of Materials The material of choice is laboratory-processed acrylic resin. It is a reasonably hard material which may be easily adjusted and is durable enough to serve as a protective nightguard. Resilient vacuformed mouthguards are of limited use. Although quick and economic to make, they are soon destroyed by determined bruxers. Their resilient surface is not amenable to the production and maintenance of a stable occlusion necessary to achieve muscle relaxation [14]. The use of hard metal alloys such as cobalt-chrome to cover occlusal surfaces is highly inadvisable as it will result in increased wear of the opposing teeth, unless worn over both the maxillary and mandibular arches (Fig. 11.7a–d). A multifactorial aetiology is common in tooth wear and, in this patient, erosive tooth wear is clearly evident but controlled prior to providing these cobalt-chrome splints to also protect against the attritional component of tooth wear. Caution is also advised in splint-wearing patients with ongoing acidic attack (e.g. in patients with gastro-oesophageal reflux) as the risk of acidic content being trapped between the under-surface of the splint and the teeth may cause further erosion. a

b

c

d

Fig. 11.7 (a–d) Maxillary and mandibular views showing tooth wear and cobalt-chrome occlusal splints

11  Occlusion and Splint Therapy

a

143

b

Fig. 11.8 (a) A Gelb appliance. (b) The effect on tooth position of wearing a partial coverage posterior onlay splint

11.6.2 Partial Coverage Splints Occlusal splints must be worn continuously, often for considerable periods of time to be effective. If a splint does not cover all the occlusal surfaces in one arch, unopposed teeth will continue to erupt creating an iatrogenic malocclusion. This applies to both anterior and posterior partial coverage splints and their use cannot therefore be recommended. Figure 11.8a shows a Gelb appliance, a partial coverage onlay splint covering only the mandibular posterior teeth, and the resulting space unintentionally created between the posterior teeth after wearing the appliance for about one year (Fig. 11.8b). When the patient closed into ICP, the posterior teeth were several millimetres apart (the thickness of the splint). The appliance provided no anterior coverage and, as a result, permitted the incisors and canines to supra-erupt and led to intrusion of the posterior segments. Conversely, a partial coverage onlay splint covering only the anterior would permit the posterior teeth to erupt, so that when the splint was removed the anterior teeth would be apart and anterior guidance would have been lost. In Chaps. 14, 15 and 16, a technique will be described where a form of anterior splint (a Dahl appliance) is used to gain space to restore worn anterior teeth. This is entirely different as it is a carefully planned procedure in which the anterior space created is filled and guidance restored with restorations placed on the severely worn teeth.

11.6.3 Maxillary or Mandibular Splints? Providing the requirements of full occlusal coverage, posterior stability, anterior guidance and use of an appropriate material are met, it matters little whether a splint is made on the maxillary or mandibular arch. In Class 1 and II incisor relationships, it is easier to produce an ideal occlusion on a maxillary appliance while the converse is true in Class III situations.

144

N. Capp and A. Eder

11.6.4 Stabilisation Versus Repositioning Splints Ramfjord and Ash [15] originally described the stabilisation or Michigan-type splint for which detailed fabrication and use will be covered in the final section of this chapter. It is a full coverage maxillary splint made from laboratory processed acrylic resin which provides anterior disclusion and stable ICP contacts between a generally flat surface and the opposing teeth. It does not seek to actively reposition the mandible into a predetermined position. It is impossible at the outset to predict the extent and direction of mandibular repositioning, and any attempt to guide the mandible more actively with the splint may actually prevent stabilisation of the retruded position. Stabilisation splints, through causing muscle relaxation, may also aid the repositioning of a displaced meniscus providing the displacement is neither too severe nor too longstanding. The use of splints which seek to reposition the mandible into a pre-determined position has been advocated, particularly in cases of internal derangement where some studies have shown them to be more effective than stabilisation splints [16]. They possess occlusal surfaces with well-defined fossae into which the opposing teeth locate with the mandible in the desired position. The problem with the use of such splints is that they may not achieve the desired masticatory muscle relaxation and it is also exceptionally difficult if not impossible to predict exactly the position in which the mandible should be located. This position is generally downward and forward from the habitual ICP, the rationale being that the stress on the disrupted joint components will be relieved, permitting them to gradually realign [17]. They also have the considerable disadvantage that following repositioning of the meniscus, the patient may be left with a posterior open bite. If this occurs, occlusal contacts may gradually re-establish through supra-eruption. Sometimes, orthodontic treatment may be necessary to re-establish occlusal stability. Because of the difficulties in use and the possible irreversible changes which may be caused to the patient’s occlusion, the use of these appliances in general practice is recommended only with caution and in experienced hands.

11.7 F  abrication, Fitting, Adjusting and Monitoring a Michigan Splint 11.7.1 Fabrication Maxillary and mandibular full arch alginate impressions are made in metal rim-lock trays. The impressions should be quickly poured with the occlusal surfaces downward to ensure accurate reproduction of surface detail. While the stone is setting the poured impressions must be stored in a humid atmosphere. A sealable plastic container with moist paper towels is ideal. When the impressions are removed, the casts should be left to dry for 24 hours; if articulated too soon, the damp stone surfaces will be abraded and rendered inaccurate. If there is likely to be a delay to pouring

11  Occlusion and Splint Therapy

145

the impressions or if multiple pours are required, high-quality silicone impressions in rigid disposable trays are a suitable alternative. The casts should be verified and then mounted in a semi-adjustable articulator using a facebow record to mount the maxillary cast (Fig. 11.9a) and an inter-­occlusal record taken on the retruded axis to establish the maxillo-mandibular relation (Fig 11.9b). The inter-occlusal registration is a pre-contact record using a rim of extra hard wax which fits accurately over the maxillary teeth without contacting the soft tissues. A fluid recording medium, such as a self-curing zinc-oxide eugenol-­ based temporary cement, is applied to the lower surface to register the cusp tips of the mandibular teeth on closure. A high-quality silicone occlusal registration material will provide a suitable alternative. Control of the mandible is improved by means of a traditional anterior jig which prevents the teeth from coming into contact making manipulation of the mandible easier and determining the vertical dimension of the record. The incisal pin of the articulator is adjusted to provide a space of about 2 mm between the most posterior teeth (Fig. 11.9c), and the outline of the splint drawn on the maxillary cast in pencil. It should extend about 3 mm onto the palatal soft tissues and wrap just over the buccal cusps and incisal edges. The splint will be retained by clipping into proximal, buccal and lingual undercuts and so these should not be blocked out prior to waxing. Two thicknesses of pink baseplate wax are softened and adapted over the cast and then trimmed to the pencil

a

b

c

Fig. 11.9 (a) Mounting the maxillary cast using a facebow record. (b) Inter-occlusal record with a rim of extra hard wax, lined with TempBond on the lower surface, and a traditional anterior jig. (c) Casts mounted providing a space of about 2 mm between the most posterior teeth

146

N. Capp and A. Eder

outline (Fig. 11.10a). The articulator is closed together until the incisal pin contacts the incisal table, establishing the vertical dimension of occlusion of the splint (Fig.  11.10b). The wax is then trimmed and the occlusion adjusted (articulating paper can be used on the wax) to establish the desired occlusion (Fig. 11.10c, d). Contacts are established between the flat surface of the splint and all opposing teeth (Fig. 11.10e) while a shallow, smooth concave ramp is built up in the anterior region (Fig. 11.10f, g) to provide immediate, but smooth, disclusion of the posterior teeth on mandibular movement (Fig. 11.10h). Once complete, the maxillary cast is removed from the articulator, invested in a flask, the wax boiled out, and then the mould packed with clear acrylic resin which is then processed (Fig. 11.11a–c). The splint is devested, cleaned, trimmed and polished and is then ready for fitting.

11.7.2 Fitting and Adjustment To fit and adjust an occlusal splint will take about 30 minutes using equipment as shown in Fig. 11.12. Firstly, the retention is tested and if too tight, acrylic resin is removed with a laboratory carbide bur from the undercut areas around the teeth until the splint seats fully and is adequately retentive. Should the splint exhibit any rocking or lack of seating despite marking of the internal fitting surface and cautious adjustment of the marked areas, it is likely that the casts were inaccurate and new impressions should be made. Accurate occlusal adjustment requires the use of very thin articulating paper held taut in Millers forceps to ensure that only the actual areas of occlusal contact are marked. The adjustment of the splint is carried out using a large laboratory carbide bur which will adjust the contacts while maintaining a flat occlusal surface. The use of too small a bur will produce indentations in the splint which are undesirable. Adjustment is carried out with the dental nurse holding two pieces of articulating paper in the patient’s mouth, one in the right and the other in the left, and the dentist providing light guidance to the patient’s chin with the patient being asked to ‘rub forward and back’ on the splint. This will guide the mandible toward the retruded position. After marking the occlusal contacts, the splint is removed and the contacts are adjusted until all mandibular teeth make even contact on the splint surface with the mandible in the retruded position (Fig. 11.13). It will probably be impossible at this stage to obtain the correct retruded position because of the state of the patient’s neuromuscular system and temporomandibular joints. Following establishment of these contacts, the splint is adjusted in lateral and protrusive movements. In lateral movements, the guidance is provided by contact between the mandibular canines and the splint surface, which separates all the other teeth (Figs. 11.14 and 11.15). In protrusive movements, disclusion is provided by even contact between the mandibular incisors and the splint (Fig. 11.16). No other teeth should make contact outside ICP.

11  Occlusion and Splint Therapy

a

147

b

c

e

g

d

f

h

Fig. 11.10 (a–h) Various stages of waxing a Michigan Splint establishing shallow anterior guidance and posterior contacts

148

a

N. Capp and A. Eder

b

c

Fig. 11.11 (a) Completed wax-up on invested cast. (b) Invested cast after wax boiled out prior to packing with clear acrylic resin. (c) Clear acrylic resin splint on maxillary cast

Fig. 11.12  Equipment required for try-in, fit and adjustment of an occlusal splint

11  Occlusion and Splint Therapy Fig. 11.13  Checking the occlusion in the retruded position

Fig. 11.14 Checking lateral movements on the working side

Fig. 11.15 Checking lateral movements on the non-working side

149

150

N. Capp and A. Eder

Fig. 11.16 Checking protrusive movements and showing disclusion of the posterior teeth

a

b

Fig. 11.17 (a) Adjusted splint showing multiple posterior contacts, anterior guidance and no interferences. The steep anterior guidance surface established in this particular case is due to the limited anterior overjet and overbite. (b) Adjusted splint—holding contacts (Black), lateral canine guidance (Red), and protrusive (Green)

Once adjustment is complete (Fig. 11.17a, b) and the adjusted splint has been polished, the patient is instructed in how to look after the splint and to wear it as much as possible.

11.7.3 Monitoring Splint Therapy If an occlusal splint is being used only as a night guard to protect teeth or restorations, it is advisable to review the patient after seven days to check whether their occlusion has remained stable and to readjust if necessary. After this, the splint should be checked at each routine examination. If the splint is being used to treat mandibular dysfunction or for pre-restorative stabilisation, the patient must be reviewed and the splint re-adjusted at weekly intervals for as long as is necessary to achieve a stable retruded position. The time necessary for this to occur may vary from a couple of weeks to several months. At each review appointment, the occlusion is re-examined and the splint adjusted to re-establish even contact and to eliminate excursive interferences. A stable

11  Occlusion and Splint Therapy

151

relationship has been achieved when the occlusal contacts marked on the splint remain unchanged for two successive appointments. If splint therapy were initiated to treat mandibular dysfunction, no irreversible alteration to the patient’s occlusion (equilibration) is generally needed. The patient may be gradually weaned off the splint but told to wear it if their discomfort returns which is often at times of stress. If the aim of splint therapy was to stabilise the mandible prior to re-organised restorative treatment, stabilisation of the occlusion on the splint must be followed by an accurate mounting of diagnostic casts in the new maxillo-mandibular relationship. Monitoring the progress of splint therapy is usually carried out by observation of the occlusal contacts on the splint at each review appointment. Prior to more complex restorative procedures and for the purposes of research, the effect the splint has on the stability of the retruded position and other mandibular border movements may be followed precisely using pantographic tracings of mandibular border movements [3, 8, 9]. The casts, once re-mounted, can then be used to plan and rehearse the restorative procedures. This may necessitate adjustment but will certainly involve diagnostic waxing.

11.8 Conclusions Patients affected by tooth wear need protective management. This is based on the elimination, where possible, of the primary cause of the wear with careful selection and use of restorative materials to improve or preserve occlusal stability. Where loads on teeth are high, an occlusal splint can be a very effective way or limiting further wear. Whilst classical fabrication techniques have been described in this chapter, developing technology in the fields of scanning, imaging and 3D printing are likely to replace these techniques over the next decade. If preventive strategies have either not been introduced or not complied with, the dentition may be very worn and fixed restorations impossible to provide. Consequently, removable prostheses are frequently used to restore those severely affected by tooth wear and Chap. 17 discusses the principles of their use. Acknowledgement  Dr Alexandra Day for permission to use the clinical images in Figs. 11.13, 11.14, 11.15, 11.16 and 11.17a.

References 1. Schaerer P, Stallard RE, Zander HA. Occlusal interference and mastication; an electromyographic study. J Prosthet Dent. 1967;17:438–49. 2. Rankow K, Carlsson K, Edlund J, Oberg T. The effect of an occlusal splint on the masticatory system. Odont Revy. 1976;27:245–56. 3. Howat AP, Capp NJ, Barrett NVJ.  A colour atlas of occlusion and malocclusion. London: Wolfe Publishing Ltd.; 1991. Chapters 2, 4, 10, 11

152

N. Capp and A. Eder

4. Furstman L. The effect of loss of occlusion on the mandibular joint. Am J Orthod. 1965;51:1245. 5. Ramfjord SP, Walden JM, Enlow RD. Unilateral function and the temporomandibular joint in Rhesus monkeys. Oral Surg. 1971;32:237. 6. Solberg WK, Clark GT, Rugh JD. Nocturnal electromyographic evaluation of bruxism patients undergoing short-term splint therapy. J Oral Rehab. 1975;12:215–23. 7. Beard CC, Clayton JA.  Effects of occlusal splint therapy on TMJ dysfunctions. J Prosthet Dent. 1980;44:324. 8. Shields JM, Clayton JA, Sindledecker LD.  Using pantographic tracings to detect TMJ and muscle dysfunctions. J Prosthet Dent. 1978;39:80. 9. Crispin BJ, Myers GE, Clayton JA. Effects of occlusal therapy on pantographic reproducibility of mandibular border movements. J Prosthet Dent. 1978;40:29–34. 10. Feinmann C, Harris M. Psychogenic facial pain—Parts I and II. Br Dent J. 1984;156:165–8. 11. Forsell H, Kirveskari P, Kangasniemi P. Changes in headache after treatment of mandibular dysfunction. Cephalagia. 1985;5:229–36. 12. Forsell H, Kirveskari P, Kangasniemi P. Response to occlusal treatment in headache patients previously treated by mock occlusal adjustment. Acta Odont Scand. 1987;45:77–80. 13. Capp NJ. Temporomandibular dysfunction – its relevance to restorative dentistry. Part 2: Splint therapy and restorative considerations. Rest Dent. 1986;2:62–8. 14. Nevarro E, Barghi N, Rej R. Clinical evaluation of maxillary hard and resilient occlusal splints. J Dent Res. 1985;64(special issue):318. Abstract 1246 15. Ramfjord SP, Ash M. Occlusion. Saunders WB Co Ltd.., 2nd Revised ed; 1971. 16. Anderson G, Schulte J, Goodkind R. Comparative study of two treatment methods for internal derangement of the temporomandibular joint. J Prosthet Dent. 1985;53:392–7. 17. Solberg WK. Temporomandibular disorders. London: BDJ Handbook; 1986. p. 96.

Tooth Wear in the Child and Adolescent

12

Paul Ashley and Kathy Harley

12.1 Introduction Whilst other chapters may have focused on tooth wear in adult patients, this problem also occurs in younger patients where it has the potential to cause severe damage at an early stage in life. There are some key differences between children and adults that will influence the management of tooth wear. The first is the anatomy of primary teeth as compared to permanent teeth. Primary teeth have relatively thin layers of enamel and dentine in comparison to permanent teeth; therefore, wear will progress faster. However, these teeth will also exfoliate. Second is the potential difficulty of providing complex care in a young and possibly anxious child. Fortunately, adhesive restorative procedures involved in the management of tooth wear involve minimal, if any, tooth preparation and can replace the enamel and dentine which has been lost without the need for further loss of tooth tissue. This allows early management rather than having to wait until adulthood. Finally, a child patient is still growing and ongoing changes in their mouth will have an effect on the occlusion and crown height. As such, any restoration should allow for ongoing adjustment until growth has stopped. Non-destructive adhesive techniques in the management of tooth wear in the child therefore have a major role to play so that the need for complex treatment can be avoided.

P. Ashley (*) Paediatric Dentistry, UCL Eastman Dental Institute, London, UK e-mail: [email protected] K. Harley Great Ormond Street Hospital for Children, London, UK e-mail: [email protected] © Springer Nature Switzerland AG 2022 A. Eder, M. Faigenblum (eds.), Tooth Wear, BDJ Clinician’s Guides, https://doi.org/10.1007/978-3-030-86110-0_12

153

154

P. Ashley and K. Harley

12.2 Epidemiology Prevalence of tooth wear in children varies between countries and is dependent on the indices used and the cut-off at which it is recorded. In general, it tends to be more common in primary teeth because the enamel and dentine is thinner. Information as to whether prevalence is increasing or decreasing is lacking. Schlueter et al. [1] reported a mean estimated prevalence in primary teeth between 30% and 50% and in permanent teeth between 20% and 45%. Tooth wear increased with age and was more prevalent in males compared to females. In the UK, the most recent data is from the 2013 Child Dental Health survey [2]. The proportion of children with tooth wear into the dentine or pulp layers of the tooth was low (4% of 15-year-olds having tooth wear into dentine or pulp on palatal surfaces of the incisors and 3% having tooth wear in dentine or pulp on the occlusal surfaces of molars). Whilst the proportion affected is low, as the authors of this report state ‘this does represent very substantial damage to have at the age of 15′.

12.3 Aetiology Tooth wear in the primary dentition is common and is usually caused by abrasion and attrition. This wear is physiological in nature and rarely needs treatment. Tooth wear in the permanent dentition is usually pathological and is a result of dental erosion. This can be a significant and difficult problem to manage. As in adults, the aetiology of dental erosion is acids that are either intrinsic or extrinsic in origin. Intrinsic acids can be related to gastro-oesophageal reflux disorders (GORD) or problems such as bulimia, both of which are covered in Chap. 5. Picos et al. [3] in their review reported that dental erosion prevalence was seen in almost all child patients with GORD. Extrinsic acids are from any acidic component in the diet with beverages thought to be the major causative factor. It is estimated that children consume sugar sweetened beverages daily [4], these beverages usually have a low pH. Interestingly, the link between beverage intake and dental erosion varies between countries with children from the Middle East being at particularly high risk [1]. Finally, there is also a link between asthma and dental erosion [5]. The actual mechanism is unclear, asthma can be associated with reduced saliva production or an increased risk of GORD both of which can cause dental erosion. Additionally, there is some data to suggest that the asthma medication delivered by the pump inhaler might itself be acidic. The development of tooth wear in an individual will be modified by a number of additional factors such as buffering capacity of saliva, the solubility of the tooth structure in acid and the relationship between the hard and soft tissues. These additional factors are similar to adults (Chaps. 3, 4 and 6). In children, unlike adults, these additional factors (e.g. xerostomia) are less likely to present.

12  Tooth Wear in the Child and Adolescent

155

12.4 Establishing the Diagnosis 12.4.1 History A medical history to establish the role of intrinsic acid is imperative with targeted questioning around any symptoms of reflux after meals. If necessary, a referral for further investigation of any gastric symptoms may be required. The need to take an adequate dietary history to explore the extent, frequency and timing of acid consumption is also important. The use of diet diaries can be particularly informative. Children and adolescents with eating disorders are discussed in Chap. 5 and close collaboration with the medical team is important. In all cases, dietary enquiries may need to be made on a number of occasions in order to match the history with the dental findings. The presenting complaint of the child or teenager is of equal importance in establishing the diagnosis and will help guide the order of treatment. This is usually one of the following: • • • • • •

Sensitivity from the teeth Pain from the teeth Chipping of the incisal edges Fracture of the teeth Incisal greying Darkening of the teeth

12.4.2 Examination Clinical examination of the anterior teeth may reveal any one or all of the following: • A loss of surface anatomy (Fig. 12.1) • Increased incisal translucency (Fig. 12.2) Fig. 12.1  A loss of surface anatomy

156

P. Ashley and K. Harley

Fig. 12.2 Increased incisal translucency

Fig. 12.3  Chipping of the incisal edges

• Chipping of the incisal edges (Fig. 12.3) • Areas where the enamel is absent (Fig. 12.4) • Exposure of the pulp (Fig. 12.5) At the back of the mouth, erosion causes a similar loss of surface anatomy, classically with cuspal cupping (Fig. 12.6), and a darkening of the colour of the teeth. However, due to the shape of the teeth, chipping is less frequent. Exposure of the pulp in the posterior teeth of the permanent dentition as a consequence of erosion is almost unheard of whereas pulpal exposure of deciduous molars in cases of severe erosion is seen more frequently (Fig. 12.7). The pattern of this erosive tooth wear can give important clues to the diagnosis. Dental erosion on the molars is more common with GORD, dental erosion on the palatal of the maxillary incisors is more commonly associated with bulimia or acidic foods (e.g. sugar sweetened beverages with a low pH). Finally, an accurate record of the extent of the tooth wear is vital so that future progression can be monitored. Indices exist to measure erosion with BEWE [6] being one of the most widely used. Photos and study casts can also be useful.

12  Tooth Wear in the Child and Adolescent Fig. 12.4  Areas where the enamel is absent

Fig. 12.5  Exposure of the dental pulp of the maxillary left central incisor

Fig. 12.6  Wear of a mandibular first molar with loss of surface anatomy

157

158

P. Ashley and K. Harley

Fig. 12.7  Pulpal exposure of the maxillary deciduous molars

12.5 Prevention of Further Erosion Once a diagnosis of dental erosion has been made, management of the condition primarily aims to prevent acid reaching the teeth. If the cause is intrinsic, then either the child will need to be referred for medical investigations or the dentist will need to liaise with the medical team supporting them. It may or may not be possible to manage the underlying medical issue but good communication with the medical team is important. If the cause is extrinsic, then advice must centre on altering the diet to remove the cause. Excessive use of acidic foods such as sugar sweetened beverages is also associated with other health problems such as obesity, so it is sensible to combine dental health messages with more general advice. Where the cause of the erosion cannot be eliminated, it is important to mitigate the effect of the erosive agent. Patients should avoid brushing teeth after exposure of the teeth to acid (e.g. after vomiting). Exposures to acid foodstuffs should be limited in frequency and where possible combined with mealtimes. Patients should be advised not to swish or hold acidic beverages in their mouth.

12.6 When to Restore Active restorative intervention is necessary: • Where there are significant areas of exposed dentine (Fig. 12.8) • Where there is a risk of tooth fracture (Fig. 12.9) • If there is hypersensitivity which cannot be controlled by any other means (Fig. 12.10). Pausing any restorative interventions until the aetiology of tooth wear is removed can be a mistake as estimating the progress of wear remains one of the most difficult

12  Tooth Wear in the Child and Adolescent Fig. 12.8 Significant areas of exposed dentine on the palatal surfaces of the maxillary central incisors

Fig. 12.9  Fracture of the incisal edges

Fig. 12.10 Widespread loss of enamel leading to hypersensitivity

159

160

P. Ashley and K. Harley

challenges faced by practitioners today. For the permanent dentition, the approach of not providing treatment until one is certain erosion has ceased is not realistic. The aims of any restorative interventions should be: • To protect the remaining tooth structure • Control symptoms • To stabilise the occlusion The management of severe tooth wear should be minimally invasive wherever possible, thereby keeping all possible future restorative options open. Several materials are available to assist in achieving these aims which differ according to whether primary or permanent teeth are being restored.

12.7 The Primary Dentition Treatment of erosion in the primary dentition is limited by patient compliance, inadequate enamel and insufficient coronal tissue to provide successful adhesive restorations. In theory, it is possible to build up worn primary incisors with composite resin, in practice this is rarely done. Provided the worn teeth remain symptom free, they are usually left unrestored until they are exfoliated (Fig. 12.11). If symptoms arise, these teeth are usually removed. Worn primary molars which are sensitive are often not amenable to successful treatment with intra-coronal restorations due to the widespread shallow nature of the erosive lesions (Fig. 12.12). Placement of preformed metal crowns on primary molars is frequently the only satisfactory way of providing relief of symptoms, cessation of continued wear and assurance that a tooth may remain in situ until exfoliation. It is also a relatively simple procedure to carry out and is well tolerated by child patients.

Fig. 12.11 Worn deciduous incisors

12  Tooth Wear in the Child and Adolescent

161

Fig. 12.12 Worn deciduous molars

Fig. 12.13  Enamel lost over a widespread area but of limited thickness

12.8 The Permanent Dentition Chapters 15, 16 and 17 consider materials currently available to treat wear in the permanent dentition. This remains an area of contention as each clinician tends to favour a particular method. To ensure placement of a satisfactory restoration in the young patient, a number of factors need to be considered: • Enamel loss is characteristically over a wide area of limited thickness (Fig. 12.13). • Anterior restorations may need regular replacement or modification as the child grows and the crown lengthens.

12.9 Anterior Restorations Where enamel loss is limited to the incisal aspect of a crown or conversely enamel loss is extensive (Figs. 12.14 and 12.15), composite resin is the material of choice. This material performs best when placed in bulk and provides an excellent aesthetic result.

162

P. Ashley and K. Harley

Figs. 12.14 and 12.15  The labial and palatal views of two extensively worn maxillary central incisors

Conventional techniques for composite placement can be used, in children use of a crown form can be helpful to simplify the procedure for the child patient. Anterior teeth should be built up to their original shape and size, even when maxillary and mandibular incisal contact has been re-established through overeruption. The patient must be warned of some discomfort immediately following composite addition; however, the occlusion will usually resolve itself through the Dahl effect [7].

12.10 Posterior Restorations Treatment for wear of the occlusal surfaces of permanent molars starts with simple approaches such as fissure sealants or use of flowable composite. These approaches are suitable for less severe cases of erosion where the occlusal height of the tooth is largely unaffected. In more severe cases of erosion with loss of occlusal vertical dimension and exposure of large amounts of dentine, more complex restorative interventions may be required. Indirect restorations are often preferable with a range of techniques available such as metal onlays, composite onlays or cad-cam restorations.

12  Tooth Wear in the Child and Adolescent

163

Fig. 12.16 Nickel-chrome onlays placed on the mandibular first molars

Evidence for the benefit of one approach over another for the management of severe dental erosion affecting the occlusal surface of permanent molars in children is lacking. Any intervention should not require tooth preparation as it is important to conserve the maximum amount of tooth structure with minimal restorative intervention. It should also support the use of axial tooth movement to recreate the space lost occlusally through wear [7]. The ideal restoration is an indirect onlay bonded directly to the tooth. Indirect composite or ceramic onlays require sufficient bulk to be viable and, therefore, are not appropriate in cases where there is insufficient space for these restorations. The authors have found success with the use of nickel-chrome (Fig.  12.16), cobalt-­ chrome or gold onlays [8] in these cases. Use of a metal as an onlay material means the restoration can be thinner whilst maintaining strength. This supports the axial tooth movement that may be required to recreate the occlusion. The appearance of these metal onlays can be an issue for some patients; however, they can be replaced as part of a more comprehensive plan when the child reaches adulthood.

12.11 Summary Tooth wear in the younger patient is due primarily to acid erosion with either GORD or consumption of acidic beverages being the most significant aetiological factors. Current data indicates that significant numbers of younger patients are experiencing tooth wear [2], and severe tooth wear in a child or adolescent will have significant long-term implications. The characteristics of the patterns of wear have been described and can be diagnostic of the underlying cause. The restorative principles are conservative and rely on adhesive techniques. When the incisal edges of the maxillary incisors have been lost, composite resin is effective only when used in sufficient bulk. The durability and predictability of adhesive nickel-chromium (cobalt-chrome) or gold onlays makes them the method of choice where posterior teeth require protection against further damage. The

164

P. Ashley and K. Harley

restorative management parallels that for adults with adhesive techniques being used whenever possible. Chapters 9 and 10 discuss the overlapping principles of treatment planning for the restorative care of those affected by tooth wear and how treatment can be ordered to deliver it effectively and the strategies that may be used to create inter-occlusal space when clinical crown height is lacking.

References 1. Schlueter N, Luka B. Erosive tooth wear: a review on global prevalence and on its prevalence in risk groups. Br Dent J. 2018;224(5):364–70. https://doi.org/10.1038/sj.bdj.2018.167. 2. ONS.  Children’s Dental Health Survey 2013: Report 2: Dental Disease and Damage in Children; 2015. https://files.digital.nhs.uk/publicationimport/pub17xxx/pub17137/cdhs2013-­ report2-­dental-­disease.pdf. 3. Picos A, Badea ME, Dumitrascu DL.  Dental erosion in gastro-esophageal reflux disease. A systematic review. Clujul Med. 2018;91(4):387–90. https://doi.org/10.15386/cjmed-­1017. 4. Dereń K, Weghuber D, Caroli M, Koletzko B, Thivel D, Frelut M-L, Socha P, Grossman Z, Hadjipanayis A, Wyszyńska J, Mazur A. Consumption of sugar-sweetened beverages in paediatric age: a position paper of the European Academy of Paediatrics and the European Childhood Obesity Group. Ann Nutr Metab. 2019;74:296–302. https://doi.org/10.1159/000499828. 5. Thomas M, Parolia A, Kundabala M, Vikram M. Asthma and oral health: a review. Aust Dent J. 2010;55:128–33. https://doi.org/10.1111/j.1834-­7819.2010.01226.x. 6. Bartlett D, Ganss C, Lussi A. Basic Erosive Wear Examination (BEWE): a new scoring system for scientific and clinical needs. Clin Oral Invest. 2008;12(Suppl. 1):S65–8. 7. Poyser N, Porter R, Briggs P, et  al. The Dahl concept: past, present and future. Br Dent J. 2005;198:669–76. https://doi.org/10.1038/sj.bdj.4812371. 8. Harley KE, Ibbetson RJ.  Dental anomalies—are adhesive castings the solution? Br Dent J. 1993;174:15–22.

Surgical Crown Lengthening in the Management of Tooth Wear

13

Richard Horwitz

13.1 Introduction When considering the prosthodontic management of a patient with tooth wear, many challenges can arise. One such challenge is how to establish the necessary inter-occlusal clearance whilst achieving adequate retention and resistance form when preparing worn teeth with short clinical crowns. To overcome this challenge, one strategy to maintain adequate crown height is to increase the occlusal vertical dimension and therefore reduce, or even eliminate in some cases, the need for further occlusal reduction of an already short tooth. However, there are limitations to increasing the occlusal vertical dimension which include the need to then restore all teeth in one or both arches as well as creating complications within the existing occlusal scheme or testing the patient’s tolerance. As a result, or when treatment needs to be provided at the existing occlusal vertical dimension, difficulties in providing adequate inter-occlusal clearance may compromise the results and surgical crown lengthening (SCL) becomes a useful alternative option. Through removal of the coronal portion of the periodontium, including gingival tissue and alveolar crestal bone, SCL aims to recreate the clinical crown height that may have been lost due to caries, fracture, delayed passive eruption, cervical resorption and tooth wear, with the latter being the focus of this chapter. Whilst exposing more tooth will create a ferrule of sound tooth tissue to assist in retaining any crowns, SCL may also improve the appearance by altering the level of the soft tissues and, as a result, showing more tooth in the right proportions once again. Both techniques have their limitations and, as a result, an increase in the occlusal vertical dimension and SCL are frequently combined to create adequate crown height with sufficient inter-occlusal clearance for the provision of predictable prosthodontic care. R. Horwitz (*) Private Practice, London, UK e-mail: [email protected] © Springer Nature Switzerland AG 2022 A. Eder, M. Faigenblum (eds.), Tooth Wear, BDJ Clinician’s Guides, https://doi.org/10.1007/978-3-030-86110-0_13

165

166

R. Horwitz

13.1.1 Site factors Limiting Surgical Crown Lengthening The following site factors might limit the crown height achievable through SCL: • • • • • • • • • •

Size of embrasure space and lip length (black triangles) Molar root morphology and furcation involvements Width of inter-dental bone Muscle insertions—position of frenula attachments Endodontic lesions Periodontitis Limited residual bone support Short roots Tapered root morphology Tooth mobility

It is, therefore, vital for the clinical assessment to screen for any dental pathology and to take appropriate radiographs to assist with diagnoses (Fig. 13.1). Position of inter-dental bone, endodontic status, root length and location of any furcations must all be considered when planning how much restorative height can be achieved. Maintaining positive bone architecture is important when planning bone removal around one aspect of a tooth, avoiding the potential to create bony defects.

13.1.2 Patient Factors Limiting Surgical Crown Lengthening These can include, but are not limited, to the following: • • • • •

Poor oral hygiene and compliance Smoking history Social or economic status Patient expectations Medical history

Alveolar bone crest

Furcation entrance

Fig. 13.1  Peri-apical radiograph used in pre-surgical planning of functional crown lengthening. This is a patient with tooth wear and primary dental disease (caries) indicated by the radiolucency on the distal aspect of tooth 46. The red line indicates the position of the alveolar crest and the positive bony architecture

13  Surgical Crown Lengthening in the Management of Tooth Wear

167

Medical contra-indications can range from immune-compromised patients to risks of medication related osteonecrosis of the jaw. Careful pre-operative assessment is, therefore, imperative before considering surgery as a viable treatment option.

13.2 A  natomical Considerations in Planning Surgical Crown Lengthening When planning SCL procedures, the clinician must consider the patient’s anatomy. At the consultation phase, the following facial and dental symmetry should be assessed: • • • • • •

Smile line (black triangles) Tooth proportions Gingival outline Gingival biotypes Keratinised gingivae Other (Table 13.1)

13.2.1 Smile Line (Upper Lip Line) The extra-oral assessment should include evaluation of the ‘smile line’. This refers to the relationship of the patient’s lips to their gums and teeth upon smiling. Making the patient feel at ease and relaxed during consultation is important in obtaining a realistic evaluation. It can also be helpful to ask patients to bring along any photographs of themselves to help assess the ‘smile line’. Table 13.2 below summarises the assessment of a patient’s gingival display. A high ‘smile line’ (Fig. 13.2) has significant implications in terms of tooth proportions and the position of the gingival margins. It is, therefore, more likely to pose significantly greater aesthetic challenges when considering SCL than patients with a low smile line (Fig. 13.3). Table 13.1  Anatomical challenges and limitations of surgical crown lengthening Anatomical challenges Position of furcation Mental foramen Unerupted teeth Dental implants Aberrant frenum

Reasoning If the tooth in question has a short root trunk, surgical crown lengthening may not be possible, with the added risk of furcation exposure Avoiding anatomical structures to preventing iatrogenic damage to nerves or blood vessels Repositioning tissues apically to increase clinical crown height may not be possible in the presence of an unerupted tooth. Removal or orthodontic management may need to be considered The placement of dental implants needs to be considered only after crown lengthening in tooth wear cases. This is so the crestal bone is not disturbed or altered Impedes plaque removal by causing pull on the gingival margin. Frenectomy may need to be considered prior to crown lengthening procedures [1]

168

R. Horwitz

Table 13.2  Assessing gingival display High smile line Moderate smile line Low smile line

Indicates visibility of gingival margins and papillae (Fig. 13.2) Indicates visibility of gingival papillae Indicates absence of gingival margins and papillae visibility (Fig. 13.3)

Fig. 13.2  Patient with a high smile line and exposure of gingival margins and papillae

Fig. 13.3  Patient with a low smile line with no marginal or inter-proximal gingival display

13.2.2 Tooth Proportions To ascertain the most appropriate tooth length and overall proportions to be re-­ established, diagnostic wax-ups and intra-oral mock-ups are essential to calculate how much additional clinical crown is required. From this, a surgical guide is fabricated to assist the clinician in providing the correct level of crown lengthening (Fig. 13.4).

13.2.3 Gingival Outline Two types of gingival outline are common in nature; straight or sinuous patterns. This is important to note as replicating the original pattern is vital to create the most aesthetically pleasing result.

13  Surgical Crown Lengthening in the Management of Tooth Wear

169

Fig. 13.4  A surgical guide is used to mark the position of the future gingival margin

Fig. 13.5  Assessing the gingival zenith

As a general rule, the gingival zenith (margin) of the central incisor and canine teeth, should be symmetrical and on the same horizontal dimension. The lateral incisor teeth, however, should either be in the same horizontal plane (straight pattern) or more coronal to adjacent teeth (sinuous pattern) (Fig. 13.5). In the majority of cases, a sinuous pattern is more common [2].

13.2.4 Gingival Biotype Gingival biotype refers to the thickness of gingivae in the bucco-lingual dimension. It is genetically predetermined and has significant implications in relation to the planning of SCL and periodontal health generally. Determination of the gingival biotype is made by assessing the shape and appearance of the gingivae or by using a UNC-15 periodontal probe and checking for translucency within the gingival tissues. The gingival biotype is of vital importance when considering crown lengthening procedures. Planning needs to take into account higher soft tissue ‘rebound’ associated with a ‘flat-thick’ gingival biotype whilst scalloped thin biotypes are associated with a higher risk of postoperative recession [3] (Fig. 13.6).

170

R. Horwitz

Fig. 13.6  Patient with a thin gingival biotype. The shape of the teeth are tapered. At the maxillary left lateral incisor site the metal abutment of a dental implant is visible through the soft tissues. The labial veneer restoring the maxillary right lateral incisor is a source of plaque accumulation and gingival inflammation. The thin biotype increases the patient susceptibility for further recession

13.2.5 Keratinised Gingivae Keratinised gingivae refers to the oral mucosa that covers the hard palate and the mucosa around the teeth. With the latter, it extends from the free gingival margin to the mucogingival junction. Keratinised gingiva is vital in maintaining gingival health and protecting the tooth from future gingival recession. It is, therefore, important to respect and retain the existing keratinised gingivae, particularly if it is in short supply. To maintain health, a minimum of 2 mm keratinised tissue is advisable [4]. Without this, the tissues are at greater risk of further recession and exposure of the restoration margins. In order to assess the amount of keratinised gingivae we have various practical ways of measuring this: • By using the side of the UNC-15 periodontal probe to create movement of the alveolar mucosa. Where the mucosa does not move, this highlights the mucogingival junction. From this we can assess height of keratinised gingivae. • Local anaesthetic can cause the alveolar mucosa to ‘swell’, delineating the mucogingival junction. • Lugol’s iodine solution to stain the alveolar mucosa, thus again highlighting the mucogingival junction and therefore the height of keratinised gingivae. When planning a SCL procedure, determining in advance how much keratinised gingivae will remain after surgery is critical with at least 2 mm remaining being required for long-term stability. If care is not taken in assessing this pre-operatively, a mucogingival deformity can be created which creates a local risk factor for future gingival recession.

13  Surgical Crown Lengthening in the Management of Tooth Wear

171

13.3 Supra-Crestal Tissue Attachment (Biologic Width) The combined dimension of the connective tissue attachment and the junctional epithelium is referred to as the ‘supra-crestal tissue attachment’ or ‘biologic width’ [5]. The dimensions (measured from 298 teeth in 30 cadavers) of the connective tissue attachment have been found to be in the range of 0.44–1.56  mm (mean 1.07 mm) and the junctional epithelium between 0.71–1.35 mm (mean 0.97 mm) [6]. This gives an average supra-crestal tissue attachment of approximately 2 mm in total. The important thing to note, however, is the range. This tells us that every patient has their own individual biologic width between approximately 1  mm and 3  mm which can also vary at different sites. This further highlights the importance of the pre-operative assessment and the need to record these measurements prior to surgery.

13.4 Bone Sounding Measuring the biologic width is done through a process referred to ‘bone sounding’. Under local anesthesia (often immediately pre-operatively), the probing depths are measured at 6–8 points around each tooth involved in surgery with a light 0.2N force. Subsequently, distance to bone is measured with greater force advancing the UNC-15 periodontal probe to the alveolar crest, through the junctional epithelium and connective tissue attachment. The difference between the probing depth and bone sounding measurement tells us more accurately the level of supra-crestal tissue attachment. Accounting for the probing depth, junctional epithelium and connective tissue is important in order to avoid biologic complications. For example, should the probing depth be 1 mm and the supra-crestal attachment 2 mm, the distance from the restorative margin to the bone must remain 3 mm. Excellent communication and a detailed prescription of what is required by the restorative dentist will be essential to inform the periodontist of precisely what is intended and the planned location of any restorative margins so that the periodontist can plan how much bone removal, if any, will be necessary.

13.5 Surgical Considerations When planning SCL, the clinician will generally follow one or other or a combination of the following approaches regarding the soft tissues: (a) resection—removal of soft tissue, or (b) an apically repositioned flap—preserving and relocating the flap apically Alongside this will be considerations regarding the underlying hard bony tissues.

172

R. Horwitz

13.5.1 Soft Tissue Management Soft tissue resection can only be considered in a situation where there is enough keratinised gingivae. If we are to remove a certain amount (dictated by the amount of clinical crown height required), at least 2 mm of keratinised gingivae must remain to prevent recession and mucogingival deformity [4]. Resection is carried out with internal bevel incisions, directed toward the alveolar crest and positioned away from the gingival margin (Fig.  13.7). The gingival contour outlined by the surgical guide would need to be followed (Fig.  13.4). If additional clinical crown height is to be achieved inter-dentally, both buccal and lingual muco-periosteal flaps will need to be raised. Conversely, approaches involving apically repositioned flaps aim to preserve the keratinised gingivae by making intra-crevicular incisions only and vertical releasing incisions to control the position of the flap to and secured with sutures at the desirable position.

Fig. 13.7 Diagrammatic overview showing the position of the blade to carry out an internal bevel incision

13  Surgical Crown Lengthening in the Management of Tooth Wear

173

Fig. 13.8  Bone removal is being carried out using piezo-surgery. The surgical guide helps to outlining the future restorative margins to aid the ostectomy

13.5.2 Ostectomy vs Osteoplasty Unless soft tissue alone can be removed to achieve the desired crown height whilst leaving at least 2 mm of keratinised gingivae and also adequate biologic width, bone will additionally need to be removed in one or both of the following ways: (a) Ostectomy refers to the removal of supporting alveolar bone, as opposed to osteoplasty which refers to the recontouring of non-supporting bone to facilitate a more ‘physiological form’ [7]. Ostectomy is vital to enable a new biologic width to be established based on the positioning of the surgical guide (Fig. 13.8), using the guide with regard to the intended location of the future restorative margin. The desired distance between the margin and the bone needs to account for the biologic width and sulcus depth. It is also important to recreate the original bony architecture on the adjacent teeth, maintaining a positive bony architecture (Fig. 13.1). (b) Osteoplasty is vital to allow satisfactory flap adaptation and to prevent a bulky soft tissue emergence or rebound of the soft tissue. Bone removal in either case can be performed safely either with hand instruments (chisels), Piezo surgical units or with burs on a surgical motor.

13.6 Restorative Considerations for Patients with Tooth Wear Respecting biologic width (supra-crestal attachment) with future restorations is also of vital importance. Restoration margins must not extend into the sulcus by more than 0.5 mm [8]. Any sub-gingivally placed margin should be considered as a risk for invasion of the biologic width leading to inflammation and periodontal disease [9]. Without taking this into account, any invasion of the supra-crestal tissue attachment can be disastrous for the long-term treatment outcome. In thin gingival biotypes, such invasion can result in clinical attachment loss through recession. Conversely, in patients with thicker biotypes, a chronic inflammatory response is normally seen although this can lead to an induced periodontitis susceptible patients [10].

174

R. Horwitz

Fig. 13.9 Inflammatory changes following invasion of supra-crestal attachment (biologic width)

Such a situation is seen in Fig.  13.9 where crown margins were placed sub-­ gingivally to maximise retention and resistance form and also hide the crown margins. This has resulted in a chronic inflammatory response and restoration margins that are impossible to clean. Whilst the intentions for sub-gingival margins may be aesthetic, the outcomes are most certainly not. SCL can assist in avoiding such negative outcomes. Planning for SCL will normally be based on the restorative treatment yet to be provided as per the agreed diagnostic wax-up. During the healing phase, the gingival margins should remain static between 6 weeks and 6 months in 85% of cases [11]. There is, therefore, a risk in a significant minority of patients for changes to be seen in the gingival margin during this timeframe. On the basis of the available evidence, when SCL is performed in the anterior zone, it is necessary to defer the provision of definitive restorations for a minimum of 3–6 months (Fig. 13.10a–c). This is to give sufficient time for post-surgical tissue maturation and stabilisation [12]. Minor adjustments to the gingival margins with further gingivectomies may also be required to perfect the final position of the gingival zeniths. Prior consent for this should be discussed with the patient at the outset and before the initial SCL procedure is carried out.

13.7 Post-operative Considerations By their very nature, surgical treatments can cause discomfort to our patients. Whilst operator skill and gentle handling of the tissues can influence this greatly, patients need to be prepared for post-operative pain. Pre- and post-surgical analgesics should be considered, including the use of non-steroidal anti-inflammatory drugs (NSAIDs), unless otherwise contra-indicated, for their positive effect on managing and reducing inflammation. With root surface exposure following SCL, patients may experience higher than usual levels of dentine sensitivity. Topical agents and pastes containing calcium sodium phosphosilicate, stannous fluoride or arginine-based products can be very effective in managing such sensitivity. The ‘occlusive technology pastes’, with

13  Surgical Crown Lengthening in the Management of Tooth Wear

a

175

b

c

Fig. 13.10 (a) Patient with tooth wear of multifactorial aetiology (erosion and attrition) with short clinical crown height. Treatment planning and diagnostic waxing informs the design and fabrication of a surgical guide to allow the clinician to assess the position of the definitive restorative margins in relation to the gingival margin and bone crest at the time of SCL. (b) Three months post-SCL of maxillary anterior teeth showing crown height gained. (c) Post-restorative treatment showing definitive restorations provided 6 months later at an increased occlusal vertical dimension

aforementioned contents, tend to be more effective at reducing sensitivity by promoting re-mineralisation of the dentinal tubules [13]. Whilst sutures are normally left for about 7 days after the procedure, patients will be instructed to avoid brushing the area. Antiseptic rinses (for example, chlorhexidine based) can be used for plaque control during this time. Once sutures are removed, however, patients should resume their normal home care regime with brushing and inter-dental cleaning to achieve optimal healing. Some bleeding can be expected for the first few days after resuming oral hygiene. Another common phenomena after periodontal surgery is a temporary increase in tooth mobility [14]. This occurs due to the increased vasculature and dilation of the periodontal ligament. It is important that patients are adequately prepared for these outcomes prior to surgery.

13.8 Conclusion Long-term periodontal health is imperative when considering SCL approaches to increase clinical crown height. In this way, restorative management of tooth wear and periodontal health are directly linked. The design of any prostheses, whether provisional or definitive, must respect the supra-crestal attachment and facilitate optimal oral hygiene care at home. Consideration must, therefore, be given to the location of restoration margins which should remain supra-gingival or at the gingival margin, wherever possible, or just into the sulcus and surgical crown lengthening is a vital tool to assist in facilitating such positive treatment outcomes.

176

R. Horwitz

At the time of writing, the world is facing a pandemic of devastating proportions with Covid-19. As a result, revised standard operating procedures are being developed to limit the risk of exposure to both patients and healthcare professionals. It is, therefore, essential that treatment is not compromised as this could otherwise lead to even more complications, such as impingement of the biologic width, and the inevitable need for even more visits and treatments. Meticulous planning, including the production of surgical guides, will all contribute to an efficient patient journey and predictable treatment outcomes avoiding the need for repeated surgical interventions and reducing complications. Moving beyond surgery, whilst provisional restorations can be provided soon after, definitive restorations should be delayed for a minimum of 3–6 months. Figure 13.10 demonstrates such an approach, taking into account the planning from a prosthodontic and periodontal perspective. A multidisciplinary approach must be considered for successful management of tooth wear and clear open dialogue between restorative clinician, surgical clinician and technicians are of vital importance for a successful patient care plan. Acknowledgements  With grateful thanks to the following: • Professor Andrew Eder for permission to use the clinical images in Figs. 13.1 and 13.2. • Dr Sandra Garcia Martin for permission to use the clinical images in Figs. 13.8 and 13.9. • Dr Linda Greenwall for permission to use the clinical images in Fig. 13.10.

References 1. Trott JR, Love B. An analysis of localized gingival recession in 766 Winnipeg High School students. Dent Pract Dent Rec. 1966;16(6):209–13. England 2. Charruel S, Perez C, Foti B, Camps J, Monnet-Corti V. Gingival contour assessment: clinical parameters useful for esthetic diagnosis and treatment. J Periodontol. 2008;79:795–801. 3. Arora R, Narula SC, Sharma RK, Tewari S. Evaluation of supracrestal gingival tissue after surgical crown lengthening: a 6-month clinical study. J Periodontol. 2013;84(7):934–40. 4. Lang NP, Löe H.  The relationship between the width of keratinized gingiva and gingival health. J Periodontol. 1972;43(10):623–7. 5. Maynard JG, Wilson RD. Physiologic dimensions of the periodontium significant to the restorative dentist. J Periodontol. 1979;50(4):170–4. Available from: http://www.ncbi.nlm.nih.gov/ pubmed/286038 6. Gargiulo AW, Wentz FM, Orban B. Dimensions and relations of the dentogingival junction in humans. J Periodontol. 1961;32(3):261–7. 7. Carnevale G, Kaldahl W. Osseous resective surgery. Periodontol 2000. 2000;22(32):59–87. 8. Goldberg PV, Higginbottom FL, Wilson TG.  Periodontal considerations in restorative and implant therapy. Periodontol 2000. 2001;25:100–9. Denmark 9. Silness J. Fixed prosthodontics and periodontal health. Dent Clin North Am. 1980;24(2):317–29. United States 10. Schmidt JC, Sahrmann P, Weiger R, Schmidlin PR, Walter C. Biologic width dimensions--a systematic review. J Clin Periodontol. 2013;40(5):493–504. United States 11. Bragger U, Lauchenauer D, Lang NP.  Surgical lengthening of the clinical crown. J Clin Periodontol. 1992;19(1):58–63. United States 12. Jorgensen MG, Nowzari H.  Aesthetic crown lengthening. Periodontol 2000. 2001;27:45–58. Denmark

13  Surgical Crown Lengthening in the Management of Tooth Wear

177

13. West NX, Seong J, Davies M. Management of dentine hypersensitivity: efficacy of professionally and self-administered agents. J Clin Periodontol. 2015;42(Suppl. 16):S256–302. 14. Kerry GJ, Morrison EC, Ramfjord SP, Hill RW, Caffesse RG, Nissle RR, et  al. Effect of periodontal treatment on tooth mobility. J Periodontol. 1982;53(10):635–8. https://doi. org/10.1902/jop.1982.53.10.635.

Orthodontic Therapy in the Management of Tooth Wear

14

Asif Chatoo

14.1 Introduction Tooth wear is a physiological process that occurs throughout life. The wear may be a result of erosion, abrasion, attrition or abfraction. The four processes probably occur together resulting in small incremental changes in the shape, form and integrity of the tooth [1]. Even though these processes are a natural occurrence, one form of wear may predominate at presentation and the tooth wear observed can be rapid and destructive. The Adult Dental Health Survey, in 2009, outlined the prevalence of tooth wear defined by three thresholds: any wear, moderate wear (wear resulting in the exposure of dentine on any surface) and severe wear (wear exposing pulp or secondary dentine). It reported that the prevalence of tooth wear has increased since 1998. Previously 11% of adults showed signs of moderate wear compared to 15% in the latest national study [2]. The decision to care for a patient presenting with tooth wear will depend on the patient’s age, the extent of tooth wear and its potential for progression that may have an impact on the long term prognosis of the teeth. Teeth that have pathological wear may benefit from treatment to help restore the deteriorating appearance and to resolve any underlying symptoms of sensitivity or pain. The challenge of managing tooth wear is primarily due to its multifactorial aetiology. As it can be a slow progressive process, it is usually accompanied by dentoalveolar compensation to maintain occlusal contact. The restorative challenge in this situation is that there is frequently insufficient space to place protective restorations without further destruction of tooth tissue. As the tooth wear becomes progressively worse the management of the dentition may also become more challenging. There is a suggestion that tooth wear due to A. Chatoo (*) The London Lingual Orthodontic Clinic, London, UK e-mail: [email protected] © Springer Nature Switzerland AG 2022 A. Eder, M. Faigenblum (eds.), Tooth Wear, BDJ Clinician’s Guides, https://doi.org/10.1007/978-3-030-86110-0_14

179

180

A. Chatoo

bruxism in the adult may be related to tooth wear that occurred as a child [3]. This would suggest that we should monitor our patients carefully from childhood and possibly provide interceptive treatment to reduce the possibility of wear of the teeth as an adult. There are several approaches to restore a dentition that has been affected by tooth wear. The creation of space with removable or fixed orthodontic appliances may contribute to easing the restorative challenge of restoring the teeth without further removal of tooth tissue. The following methods can be used to create space to facilitate the restoration of teeth: • A fixed or removable bite platform such as a Dahl appliance • Orthodontic treatment with or without the use of a temporary anchorage device

14.2 Dahl Appliance The ‘Dahl Concept’ refers to the re-establishment of the occlusion following the relative axial movement of the teeth on placing a localised appliance (or restorations) that is in supra-occlusion [4]. The concept of the axial movement of teeth was not new as it had been, and still is, commonly used with removable orthodontic appliances to reduce a deep overbite in growing patients. However, in 1975, Dahl and colleagues reported using a removable anterior bite platform, constructed in cobalt chromium, to create inter-occlusal space to facilitate the restoration of worn palatal surfaces of incisors in a young adult patient [5]. The original Dahl appliance covered the cingula of the upper anterior teeth and was retained by clasps on the canine or premolar teeth. The platform caused disclusion of the posterior teeth as the lower incisors contacted the anterior bite platform. Subsequently, an alternative approach using a fixed metal prosthesis cemented on the palatal surfaces of the upper anterior teeth in supra-occlusion has also been described [6]. The construction of the bite platform must allow for the occlusal forces to be directed along the long axes of the teeth to be moved. The newly created inter-­ occlusal contacts need to be stable and the platform must not impede the movement of the discluded teeth. The thickness of the platform and the change in the occlusal vertical dimension depends on the inter-occlusal space required for the restorations. Over a period of time, the posterior teeth erupt leaving sufficient inter-occlusal space for the restoration of the palatal surfaces of the upper anterior teeth. Dahl and Krogstad reported that the process, over a period of 4–6 months, involved the of controlled intrusion (40%) and extrusion (60%) of the dento-alveolar segments [7]. There may also be an element an accompanying mandibular repositioning involving the condyles [8]. The Dahl concept cannot be used in all patients with anterior tooth wear. Hemmings and co-workers indicated limitations in the success of using the anterior

14  Orthodontic Therapy in the Management of Tooth Wear

181

bite platform in patients presenting with a class III malocclusion and facial asymmetry where there was an absence of stable occlusal contacts in the inter-cuspal or retruded positions [8].

14.3 Orthodontic Treatment Considerations In many cases, a restorative approach to treatment may suffice. However, in situations where there is an underlying malocclusion or crowding that needs to be resolved, orthodontic treatment may be beneficial as an intermediary step in the treatment plan. If a multidisciplinary approach to treatment is indicated and orthodontic treatment is recommended the patient must be evaluated independently and together by the treating restorative and orthodontic specialists. The role of orthodontics may either be simply as an adjunct to treatment or have a greater role in establishing a better occlusion. Either way, the primary purpose of treatment will be to create the required space for restoration of the teeth. It is essential that a clear list of objectives with the limitations of each treatment are noted and explained to the patient.

14.4 Examination of the Patient A thorough examination is always required to determine the skeletal pattern in all three dimensions. An assessment of the temporomandibular joints is recommended to determine mandibular opening, deviation of the mandible on closing, and any associated pain, clicking or dysfunction. Intra-oral examination of the hard and soft tissues along with a periodontal assessment is essential. Finally, determining the occlusal relationship, the functional relationship and the presence of an underlying malocclusion will help complete the initial evaluation. There are differences in the location and pattern of tooth wear observed between different malocclusions [9, 10]. The presence of crowding and irregular functional relationships due to a crossbite or anterior open bite may also influence the pattern of wear that may be observed. On assessing the tooth wear, the type of wear, the location and extent of the lesions, and the severity should be recorded. Full diagnostic records should include mounted study casts to evaluate any deflective contacts in the current occlusion, photographs and long cone periapical radiographs. Once the appropriate preventive measures have been taken, such as dietary advice in cases of erosion, removal of any deflective contacts in cases of attrition or provision of a splint to minimise the effects of parafunction, orthodontic treatment may be considered. It is also imperative that any other pathology has been treated and the patient is dentally healthy and stable. The type and extent of orthodontic treatment will depend on the final restorative objectives and the amount of overbite reduction that may be required.

182

A. Chatoo

14.5 Appliances There are several orthodontic approaches to create the required inter-occlusal space with overbite reduction when a patient presents with anterior tooth wear. These are incisor proclination, incisor and canine intrusion of the upper and lower teeth and buccal segment (premolar and molar) extrusion [11]. The treatment of choice may depend on the various features of the underlying malocclusion, the aetiology and extent of tooth wear and the age of the patient. The type of tooth movement desired will influence the decision to use a removable appliance, a fixed appliance or a combination of both. If simple tipping tooth movement is required for proclination of the upper incisors, a removable appliance with springs can provide the required tooth movement. The main limitation of a removable appliance in an adult patient is the compliance and tolerance of the device. When full three-dimensional control of the tooth movement is desired fixed braces are indicated. The intrusion of the incisors may be indicated where bite opening and increasing the occlusal vertical dimension of the posterior teeth is contra-­ indicated. The decision on whether to intrude the maxillary or mandibular incisors should take into account which teeth have been most affected by wear and by a functional evaluation of the position of the upper gingival margins with regard to the upper lip [12]. The intrusion of the incisor teeth only requires very light forces (10–20  g of force) that are precisely directed. A variety of orthodontic treatment mechanics can be employed to facilitate overbite reduction with the intrusion of the incisor teeth. The Begg and Tip-Edge techniques are characterised by the use of a combination of rigid steel arch wires, that bypass the premolar teeth, and light inter-maxillary elastics. The initial phase of treatment allows for the simultaneous alignment of the teeth as the overbite is reduced along with the overjet. With pre-adjusted edgewise appliances that are more commonly used in orthodontics, the process of overbite reduction begins following the completion of the initial alignment of all the teeth including the second molars. Elastics and a rigid continuous stainless steel arch wires are then introduced, with or without a reverse curve of Spee, to control the overbite. The introduction of lingual crown torque can be useful to control any undesired lower incisor proclination. The use of elastics in both techniques described may cause the undesirable extrusion of the molar teeth. The use of a utility arch, or segmental mechanics bypasses the buccal segments and applies a direct intrusive force to the incisors [13]. They can be used in conjunction with a pre-adjusted edgewise appliance and provide a mechanically efficient way means to intrude the incisors without using elastics. However, they are more difficult to fabricate and create a step in the occlusal plane. In many instances, orthodontic treatment to facilitate treatment of tooth wear occurs in adults. On some occasions, the patient may reject orthodontic treatment on the grounds of the appearance of conventional labial appliance. In these cases, lingual braces can also be effectively used to achieve the orthodontic goals for treatment.

14  Orthodontic Therapy in the Management of Tooth Wear

a

c

183

b

d

Fig. 14.1 (a) Frontal view showing differential wear of anterior teeth also noting dento-alveolar compensation of the UL1 and UL2 has occurred. (b) Frontal view showing the teeth following orthodontic treatment to intrude the maxillary and mandibular incisors to create space for restoration of the maxillary incisors. (c and d) Frontal and occlusal views following home tooth whitening and restorative treatment with the addition of tooth coloured composite resin to extend the lengths of the maxillary anterior teeth and white gold adhesively retained palatal veneers by way of protection. A night-time Michigan Splint was provided to reinforce orthodontic retention and help protect teeth and restorations from night-time bruxism

The choice of technique will depend on the preference of the treating clinician. As with most aspects of dentistry, each technique has advantages and disadvantages. These must be considered before a final treatment approach is selected. Following orthodontic treatment, restorations may be placed to restore the shape, form and integrity of the upper and lower teeth (Figs. 14.1a–d and 14.2a–e). The restorations must provide contacts on mandibular closure and stability of the teeth in their new position.

14.6 T  he Role of Mini-Implants as Temporary Anchorage Devices An orthodontic mini-implant (OMI), sometimes referred to as a temporary anchorage device or TAD, is a medical grade titanium alloy screw that can be inserted into the alveolar bone to provide anchorage to facilitate tooth movement (Chap. 18). Costa and colleagues described the use of ‘mini-screws’ to provide anchorage for tooth movement in 1998 [14]. Since then, OMIs have revolutionised anchorage reinforcement in all forms of orthodontic treatment. The advantages of using of OMIs in orthodontics are: • They are easy to insert • It is possible to place them in various areas depending on the type of anchorage desired

184

A. Chatoo

a

b

c

d

e

Fig. 14.2 (a and b) Frontal and maxillary occlusal pre-treatment views showing significant anterior and posterior tooth wear. (c–e) Frontal and occlusal views showing the situation toward the end of orthodontic treatment. Occlusal stops with glass ionomer cement have been added to the occlusal surfaces of the molar teeth to test the increase in the occlusal vertical dimension for additive restorations on the occlusal surfaces of the posterior teeth. Space has also been created to allow restoration of the palatal surfaces of the maxillary incisors and the incisal edges of the mandibular incisors

• • • • •

A force can be applied immediately after placement They can safely be left in situ for several months The OMI is easily and painlessly removed The site heals quickly following removal of the OMI OMIs are relatively inexpensive

OMIs may be used for direct or indirect anchorage. With direct anchorage, the application of force is provided by direct attachment to the OMI. Indirect anchorage refers to the OMI being connected to the anchor teeth to reinforce their position and to avoid any undesirable movement. When intrusion is required in managing patients with tooth wear, the OMI may be placed in the region where the intrusion is desired and the force applied directly to the teeth via the fixed appliance. The advantage of this approach is that a gentle force may be applied that is directed along the long axis of the teeth to be moved,

14  Orthodontic Therapy in the Management of Tooth Wear

185

close to the centre of resistance of the teeth. OMIs can be a very effective way of intruding the incisor teeth or even molar teeth to facilitate the creation of inter-­ occlusal space to allow additive restorations with minimal tooth preparation and further loss of tooth tissue. OMIs are now a common method of treatment in orthodontics with versatility, minimal invasiveness and a positive relationship between cost and the benefits that they offer. The simplification of procedures for insertion and the versatility of the mechanics have made the use of such mini-implants a routine in clinical practice and have eliminated the need for complex laboratory procedures. When maximum anchorage is necessary, the mini-implants appear to be a new alternative in orthodontic treatment, since these devices are inserted in the bone providing effective anchorage (skeletal anchorage). Skeletal anchorage has, to a large degree, replaced conventional anchorage in situations where anchorage is considered either critical, insufficient, or likely to result in undesirable side effects such as vertical displacements. A systematic review of the literature has shown that OMIs are more effective in preventing unwanted and undesirable tooth movement than previous conventional methods for anchorage support [15].

14.7 Conclusion Guided eruption or conventional orthodontic tooth movement should be contemplated when establishing a treatment plan to create inter-occlusal space to allow re-establishing the shape, form and integrity of teeth that have been damaged by tooth wear. Use of the Dahl principle is effective in creating inter-occlusal space in the absence of an underlying malocclusion and crowding. However, in more complex situations, comprehensive orthodontic treatment may be a useful strategy to create the necessary space to restore the dentition, while minimising the complexity of the underlying restorative challenge and preventing further loss of tooth tissue in the preparation of the teeth for protective restorations. Acknowledgement  Professor Andrew Eder for permission to use the clinical images in Figs. 14.1 and 14.2.

References 1. Hemmings K, Truman A, Shah Tooth Wear S.  Guidelines for the BSRD Part 1: Aetiology, diagnosis and prevention. Dent Update. 2018;45:3–10. 2. Digital NHS. Adult Dental Health Survey 2009—summary report and thematic series [NS]. London: The Health and Social Care Information Centre; 2011. [Available from: https:// digital.nhs.uk/data-­a nd-­i nformation/publications/statistical/adult-­d ental-­h ealth-­s urvey/ adult-­dental-­health-­survey-­2009-­summary-­report-­and-­thematic-­series] 3. Knight DJ, Leroux BG, Zhu C, Almond J, Ramsay DS. A longitudinal study of tooth wear in the orthodontically treated patients. Am J Orthod Dentofac Orthop. 1979;112(2):194–202.

186

A. Chatoo

4. Poyser NJ, Porter RW, Briggs PF, Chana HS, Kelleher MG. The Dahl Concept: past, present and future. Br Dent J. 2005;198(11):669–76. 5. Dahl BL, Krogstad O, Karlsen K. An alternative treatment of cases with advanced localised attrition. J Oral Rehabil. 1975;2:209–14. 6. Ibbetson R, Setchell D. Treatment of the worn dentition: 2. Dent Update. 1989;16(7):300–7. 7. Dahl B, Krogstad O. Long term observations of an increased occlusal face height obtained by a combined orthodontic/prosthetic approach. J Oral Rehabil. 1985;12(2):173–0. 8. Hemmings K, Darbar U, Vaughn S. Tooth wear treated with direct composite at an increased vertical dimension: results at 30 months. J Prosthet Dent. 2000;83(3):287–93. 9. Oltraman-Navarro PVP, Janson G, de Oliveira RBS, Quaglio CL, Henrique JFC, de Carvalho Sales-Peres SH, McNamara JA. Tooth wear patterns in adolescents with normal occlusion and Class II Division 2 malocclusion. Am J Orthod Dentofac Orthop. 2010;137(6):730.e1–5. 10. Janson G, Oltraman-Navarro PVP, de Oliveira RBS, Quaglio CL, de Carvalho Sales-Peres SH, Tompson B. Tooth wear patterns in subjects with Class II Division 1 malocclusion and normal occlusion. Am J Orthod Dentofac Orthop. 2010;137(1):14.e1–7. 11. Bennett JC, McLaughlin RP.  Management of the deep overbite with preadjusted appliance system. J Clin Orthodont. 1990;24(11):684–96. 12. Sarver DM. The importance of incisor positioning in the esthetic smile: the smile arc. Am J Orthod Dentofac Orthop. 2001;120(2):98–111. 13. Burstone CR. Deep overbite correction by intrusion. Am J Orthod. 1977;72:1–22. 14. Costa A, Raffainl M, Melsen B. Mini-screws as orthodontic anchorage: a preliminary report. Int J Adult Orthodon Orthognath Surg. 1998;13(3):201–9. 15. Jambi S, Walsh T, Sandler J, Benson PE, Skeggs RM, O’Brien KD.  Reinforcement of anchorage during orthodontic brace treatment with implants or other surgical methods. Cochrane Database Syst Rev. 2014;2014(8):CD005098. https://doi.org/10.1002/14651858. CD005098.pub3.

Adhesive Restorations

15

Sophie Watkins, Matthew Jerreat, and James Baker

15.1 Introduction Adhesive dentistry techniques were first developed in the 1960’s following Buonocore’s description of the acid etch technique [1] using phosphoric acid. The later introduction of dentine bonding agents [2] and silane primers, along with ongoing development of the characteristics of composite resins as restorative materials and their use as luting cements, has meant that a predictable bond that can be achieved between tooth tissue and a variety of materials. This includes composite resin as a restorative material, or as a luting cement for bonding metal alloys and etchable ceramics. This has resulted in adhesive techniques being utilised in a wide variety of applications within dentistry and their widespread use in clinical practice. In many respects, the development of adhesive dentistry has simplified much of the restorative management of patients with worn teeth, as an alternative to many traditional treatment strategies, such as full coverage conventional crowns. A primary goal in tooth wear management is the preservation of remaining tooth structure. Whilst conventionally cemented full or partial coverage restorations may still be indicated in a limited number of cases, such a destructive approach (Fig. 15.1a, b) must be considered counter-intuitive. Therefore, the attractiveness of adhesive

S. Watkins Restorative Dentistry, Guys and St Thomas’ NHS Foundation Trust, London, UK e-mail: [email protected] M. Jerreat Restorative Department, Musgrove Park Hospital, Taunton, UK e-mail: [email protected] J. Baker (*) UCL Eastman Dental Institute, London and Peninsula Dental School, University of Plymouth, Plymouth, UK e-mail: [email protected] © Springer Nature Switzerland AG 2022 A. Eder, M. Faigenblum (eds.), Tooth Wear, BDJ Clinician’s Guides, https://doi.org/10.1007/978-3-030-86110-0_15

187

188

a

S. Watkins et al.

b

Fig. 15.1  Conventional tooth preparation is very destructive of tooth tissue. (a) Conventional full coverage preparation. (b) Conventional full coverage preparations (maxillary right central and lateral incisors) contrasted with more conservative partial coverage preparations (maxillary left central and lateral incisors) demonstrating the significant amount of tooth tissue that can be preserved where such an approach is employed

procedures in restoring worn teeth and protecting them from further wear is a result of both their conservative nature and relative reversibility. As technology advances and practitioners become more comfortable with adhesive dentistry, the indications for a conventional approach are becoming increasingly rare. These innovations require modification of established techniques, as described in more detail in this chapter.

15.2 Case Selection As with all treatment, appropriate case selection is key to a successful outcome. This requires correct diagnosis and assessment of prognosis, patient factors and operator skill and experience. Diagnosis of tooth wear, specifically aetiology followed by successful stabilisation, are described in other chapters, and will therefore not be discussed here. However, it is vital to stress the importance of appropriate prevention and monitoring so that tooth wear is at least reasonably well controlled prior to definitive restoration, as this significantly affects prognosis. The main factors to consider are: • • • • •

Aetiology Extent of tooth tissue loss Patients expectations and wishes Ability to attend for appointments Financial considerations

15  Adhesive Restorations

189

15.3 Treatment Planning 15.3.1 Direct vs Indirect Restoration Adhesive dentistry was initially limited to direct techniques, primarily the use of composite resin restorations, and whilst this still has a significant part to play and can offer excellent aesthetics, the application of adhesive technology to adhesive luting cements has transformed the options available by making a range of indirect adhesive restorations a realistic alternative. This affords the potential for optimal preservation of remaining tooth structure in a way that is not possible with conventional tooth preparation (Fig. 15.1). Adhesive technology has enabled the clinician to utilise more durable and conservative cast metal partial coverage restorations in low aesthetic and high load areas.

15.3.2 Timing Although all efforts should be made to identify and control the cause of tooth wear, the authors acknowledge that the aetiology is usually multifactorial, and it is therefore not always possible to reach a definitive diagnosis. This should not be an absolute barrier to providing treatment where there is a risk of losing valuable enamel for bonding. Therefore, treatment is sometimes provided at an early stage of wear progression and may be indicated when the cause of wear has not been identified, tooth wear is progressing in spite of a preventive regime, or if there are aesthetic concerns, tooth sensitivity or extensive areas of exposed dentine. Early signs of wear, such as cupping of the cusp tips or the incisal edges, can be addressed with simple direct adhesive restorations (Fig. 15.2) if symptoms have not been controlled or the cause of wear has not been reliably addressed. It is worth noting, however, that direct composite resin is more liable to failure if applied in thin sections, such as in shallow areas of cupping, and should be considered relatively high maintenance and not suitable for the palatal aspects of maxillary incisor teeth unless sufficient bulk can be applied for strength of the material (see Sect. 3.5.1 on the ‘Dahl concept’).

15.3.3 Site The site of wear and whether it is localised or generalised are significant factors in treatment planning. Whilst restoration of non-occluding areas is relatively straightforward, where a functional (occluding) surface is affected and requires restoration, this requires more careful planning with regard to occlusal scheme and material choice.

190

S. Watkins et al.

a

b

c

d

Fig. 15.2  Early tooth wear can be restored with direct composite resin. (a) Maxillary teeth: pretreatment. (b) Maxillary teeth: post-treatment. (c) Mandibular teeth: pre-treatment. (d) Mandibular teeth: post-treatment

15.3.4 Cervical Wear Cervical tooth wear lesions present in a variety of forms depending on aetiology and may not all require restoration. However, if aesthetics, sensitivity or structural considerations dictate, restoration with an adhesive material is appropriate. Such lesions are usually simple to restore and a variety of materials are available. Where the margins of the lesion are confined within enamel, composite resin offers a durable and aesthetic solution (Fig. 15.3). However, the lesions frequently extend to involve the root surface and although dentine bonding is now well established and predictable, consideration should be given to moisture control in these areas, and glass ionomer cement may be more appropriate. This has the additional advantage of a dynamic bond to dentine and fluoride ion release, which may offer some protection from secondary caries. However, and despite continued developments, including hybrid or resin modified materials, the aesthetics of such materials do not tend to be as favourable, and composite resin and associated bonding agents offer more predictable options. Tooth brushing technique is an important factor to address as toothbrush abrasion is a frequent cause of cervical wear, and all efforts should be made to identify and control aetiological factors prior to restoration unless symptoms or other factors dictate otherwise.

15  Adhesive Restorations

191

Fig. 15.3  Cervical and proximal abrasion caused by oral hygiene technique, before (left) and after restoration (right) with direct composite resin

Fig. 15.4  Blasting with aluminium oxide (left) to prepare cervical abrasion lesions prior to restoration with composite resin (right)

One issue with bonding to cervical dentine lesions is that the surface is highly polished. Blasting the tooth surface with 50 μm aluminium oxide (Al2O3) (Fig. 15.4) can leave a very clean and roughened surface with a greater surface area and energy for bonding which can improve dentine bond strengths.

15.3.5 Occlusal Wear 15.3.5.1 General vs Localised Wear involving occluding tooth surfaces is associated with a degree of alveolar compensation, which maintains contact between the worn teeth and no discernible loss of occluding vertical dimension (OVD) (Fig. 15.5). Restoration at an increased OVD avoids the need for unnecessary and destructive occlusal tooth reduction. This must be planned carefully, including the use of study casts mounted on a semi-adjustable articulator with the aid of a face-bow and retruded records. If tooth wear is generalised, space for restorative material can be created by the restoration of worn teeth in one or both arches at an increased OVD, utilising adhesive onlays or more traditional partial coverage restorations where appropriate, in order to avoid destructive occlusal tooth preparation. Where tooth wear is localised, alveolar compensation results in contact being maintained between the worn teeth, resulting in lack of space for restoration of the

192

S. Watkins et al.

Fig. 15.5  Alveolar compensation resulting in the worn anterior teeth maintaining contact in spite of palatal wear

Fig. 15.6  Composite ‘Dahl’: maxillary anterior teeth have been built up, intentionally taking the posterior teeth out of inter-occlusal contact, which has subsequently been re-established as a consequence of alveolar compensation

lost tooth tissue. Space creation for restoration of localised tooth wear may be achieved by restoration at an increased OVD using a ‘Dahl appliance’ [3] to cause alveolar compensation by relative axial movement of the teeth. This avoids the need for extensive restoration of unaffected teeth to achieve the required inter-occlusal space to restore the worn teeth. The ‘Dahl concept’ is now a widely accepted and established technique for space creation, and has been adapted since it was initially described, where an interim removable or fixed appliance was placed during the orthodontic phase. Definitive restorations are now routinely placed ‘high’ in occlusion, where there is a need to create inter-occlusal restorative space. After a period of time, alveolar compensation occurs with intrusion of some teeth and over-­ eruption of others, resulting in occlusal contacts re-establishing between those teeth initially held out of occlusion by the ‘high’ restorations [4] (Fig. 15.6). Increases in vertical dimension are generally well tolerated by dentate patients, due to proprioception through the periodontal ligament and associated neuromusculature [5]. Clinical studies in adults have not reported any long-term increase in temporomandibular dysfunction (TMD) or dental problems [6]. Occlusal splints (Chap. 11) are therefore not always necessary to simply test an increase in OVD but may still be indicated for other reasons including pre-restorative stabilisation to ensure a reproducible jaw relationship, protect worn teeth/new restorations if there is an attritive co-factor, and in the management of TMD [7].

15.3.5.2 Anterior Wear Anterior tooth wear frequently affects the palatal and incisal aspects of maxillary teeth and incisal and labial aspects of lower incisors. As these are occluding

15  Adhesive Restorations

193

surfaces, space creation to accommodate the restorative material is required, and in order to avoid further tooth reduction, with its associated biological and mechanical compromise, space creation techniques described above should be employed. When palatal wear is advanced (Fig.  15.7), thinning of the incisal edges may present as an apparent blueish discolouration due to increased translucency. In these circumstances, there is a significant risk of fracture of the weakened tooth structure and further thinning, shortening clinical crown height with associated aesthetic concerns. Unchecked, this can become an ongoing cycle of thinning and bulk fracture and intervention is highly recommended to prevent rapid worsening of the condition. Discussion with the patient regarding their aesthetic concerns at presentation is key to treatment planning, as protection of remaining tooth structure is considerably more straightforward than restoration of lost incisal height. In this instance it is imperative that the wear is predictably controlled and monitored. If the patient is happy to accept the presenting tooth display, restoration can be limited to protection of the remaining tooth structure on the palatal aspect. This affords a wider choice of restorative material as metal remains an option (Fig. 15.8), since it can be concealed from view and offers the advantage of being less prone to fracture, being strong in thin section, and therefore more desirable as a low maintenance long term option [8, 9]. Gold coloured precious metal alloys are less aesthetically intrusive than greyer non-precious or semi-precious options, although the latter are more cost effective,

a

b

c

Fig. 15.7 (a) Palatal wear leading to incisal ‘shine through’. (b) and (c) Left unprotected, this can lead to a cycle on thinning and fracture with associated shortening of the teeth, and a complex restorative challenge

194

S. Watkins et al.

even more rigid in thin section and are more easily able to form an oxide layer that bonds to adhesive resins containing 10-methacryloyloxydecyl dihydrogen phosphate (MDP). It should be noted that the thinned incisal aspect is likely to exhibit ‘shine through’ of the palatal restorative material, and concern is often expressed regarding ‘greying’ of incisal edges as a consequence. This can be overcome by using an opaque luting cement to mask the colour of the metal, as used for the cementation of resin-retained bridges [10]. However, whilst this can be very effective in masking the colour of the metal, the placement of any opaque material on the palatal aspect of an incisor will result in a loss of translucency which will alter the shade, and this must be accounted for when planning treatment (Fig. 15.9a–c). For optimum protection against ongoing wear, the metal palatal veneer should be extended onto the incisal edge (Fig. 15.8). This allows accurate seating of the restoration and utilisation of the maximum available bonding area, whilst affording some degree of protection of the cement lute from shear forces, optimising the prognosis and predictability of such restorations. This is also often where the tooth is most fragile and in need of protection. Fig. 15.8  Palatal view showing gold veneers extending just over the incisal edges (maxillary right first premolar incorporating design features for a removable partial denture)

a

b

c

Fig. 15.9 (a) Shade taking must take account of potential alteration in translucency when planning to use an opaque resin luting cement. This can be achieved by (b) placing a cotton wool roll or gloved finger behind the teeth or (c) using an opaque material such as TempBond to mimic the loss of translucency and aid shade selection

15  Adhesive Restorations

195

Patients and practitioners often express concern that this design will be aesthetically unacceptable and there is a temptation to cut short the incisal extension and accept the functional compromise that this may present. However, as the clinical photographs demonstrate (Fig.  15.10), as long as the metal incisal extension is tapered to a feather edge finish, the result can be almost undetectable labially, especially when the teeth are apart as in normal conversation (Fig. 15.10a). Where there is a need for restoration of incisal height, a tooth-coloured option is required, either in the form of a direct composite build-up, or an indirect approach. Direct composite resin build-up can offer an excellent aesthetic outcome (Fig. 15.11) a

b

c

Fig. 15.10  Gold palatal veneers demonstrating loss of incisal translucency when opaque luting cement is used, and how extension to the incisal edge can be unobtrusive, whilst achieving maximum protection against future wear. (a) Labial view with teeth apart showing loss of translucency and good aesthetics in spite of incisal extension being just visible. (b) Labial view with teeth together with incisal extension being just visible. (c) Buccal view Fig. 15.11 (a and b) Direct composite is a cost-effective option where sufficient bulk of composite can be used for strength

a

b

196

S. Watkins et al.

and is more cost effective as laboratory costs are not involved. However, this is a technique sensitive and time-consuming approach if optimal aesthetics are to be achieved. Provided there is sufficient space available to allow a bulk of composite for strength, or if this space can be created, this is a predictable technique which has the advantage of being repairable [11–13]. Maintenance, though low grade, is high frequency compared to indirect techniques [14, 15] and patients should be warned of this as part of the informed consent process (Chap. 8), bearing in mind the relative advantages of the minimally destructive technique compared to more conventional approaches. These require less medium-term maintenance but may be considered to compromise long term tooth survival [16]. A protective mouthguard, such as a Michigan Splint (Chap. 11), is indicated to improve the lifespan of any definitive restoration (Fig. 15.12). Alternatively, indirect restorations can be provided which also require minimal or no tooth preparation (Figs. 15.13 and 15.14). Metal palatal veneers can be provided either after placing direct composite resin (Fig. 15.11b) to restore lost incisal and labial tooth tissue, or the metal design can be modified to incorporate space for addition of direct composite resin placed at fit [17] (Figs. 15.25 and 15.26). Alternatively, tooth-coloured indirect restorations can be provided to restore palatal and incisal tooth form (Fig. 15.13b). The latter has been described using palatal and incisal ceramic, whilst recent developments in the physical properties of composite based materials have resulted in these being a realistic alternative to ceramic, with the advantage that visible margins on the

a

b

Fig. 15.12  (a and b) A Michigan Splint is indicated to protect definitive restorations

a

b

Fig. 15.13 (a) Gold and (b) indirect composite palatal veneers restoring upper canine to canine

15  Adhesive Restorations

197

a

c

b

d

Fig. 15.14  Use of indirect tooth-coloured restorations (Ceramic: (a) and (b), Composite: (c) and (d)) to treat maxillary and mandibular anterior tooth wear

labial aspect can be more easily masked with direct resin, which bonds more predictably to these materials than to ceramic. Whichever approach is adopted, some masking of the junction between indirect restoration and tooth is required, and this can be achieved with direct composite resin placed after cementation of the laboratory-made restoration. The direct composite resin component of the restoration may be subject to faster deterioration than the laboratory produced elements, with a higher maintenance burden associated with this. An alternative approach is to provide a metal palatal veneer in conjunction with a ceramic laminate veneer labially, although this complicates the design and predictability, as it is associated with a complicated combination of margins finished to both tooth and adjacent restorative material. Careful consideration should be given to whether a conventional full veneer crown or minimal preparation resin or ceramic crown restoration is more appropriate (Fig.  15.14) in cases where extensive tooth tissue requires replacement. It is important to weigh up the advantages and disadvantages of maintenance against preservation of tooth structure. Study casts mounted on a semi-adjustable articulator with the aid of a face-bow and, normally, retruded records are required for planning, especially where an increase in incisal length is required, and a diagnostic wax-up should be produced to determine the final desired contour prior to treatment (Fig. 15.23). This allows for diagnostic previews and intra-oral ‘mock up’ (Fig. 15.24) to demonstrate the possible aesthetic result to the patient before definitive restoration is planned. Digital technology (Figs. 15.15 and 15.23) can be utilised to facilitate the planning process, allowing restorations to be designed and fabricated using CAD-CAM and scanning techniques.

198

S. Watkins et al.

Fig. 15.15  Digital laboratory design

15.3.5.3 Posterior Wear In general, localised posterior occlusal tooth wear is less common than in the anterior region, since it tends to come about following wear to the guiding surfaces of the anterior teeth. However, it may be seen in isolation in cases that lack guidance on anterior teeth such as in patients with a Class II Division I or a Class III malocclusion or an anterior open bite. As with all forms of occlusal tooth wear, the most challenging aspect of managing such patients is creation of adequate inter-occlusal restorative space. If the posterior occlusal wear forms part of a general pattern of wear, often the most appropriate approach is to first restore the anterior teeth at an increased OVD, but rather than allowing re-establishment of posterior contact, use the space created to restore the posterior occlusal surfaces. Since there will often be a delay between restoring the anterior teeth and the posterior teeth, a space holding material such as glass ionomer cement or composite resin may be used as discrete stops on the occlusal surfaces of the teeth in one arch (Fig. 15.16). When deciding which material is most appropriate for the restoration of posterior teeth with tooth wear, a number of factors need to be carefully considered. Firstly, it is essential to identify the aetiology. The mechanical characteristics of the restorative material are less crucial in erosive cases, in contrast to cases where attrition is the primary cause, as the latter are likely to be subject to high occlusal forces. However, in erosive cases, cements which may be soluble in acid environments such as glass ionomer cements should be avoided. The second factor is related to the occlusion. Patients with anterior guidance on anterior teeth will subject their posterior restorations to lower lateral forces than those with anterior teeth out of contact, such as anterior open bite, incomplete overbite or severe Class III with edge-to-edge or reverse incisal relationships.

15  Adhesive Restorations

a

199

b

Fig. 15.16  Mandibular occlusal stops in (a) glass ionomer cement or (b) composite resin to prevent loss of restorative space prior to definitive restoration of posterior teeth

Thirdly, determining the quality and quantity of remaining tooth tissue is critical. Adhesive restorations require a substrate of natural tooth tissue, preferably with the marginal area completely in enamel. Conventional restorations have no such requirement and rely entirely on the principles of retention and resistance form, but this necessitates adequate axial wall height which is often limited in cases of occlusal wear, as well as necessitating removal of precious axial tooth tissue. The fourth factor is consideration of the patient’s aesthetic demands. For example, most patients may be happy to accept cast metal restorations on their upper second molar teeth but less so on their premolars and lower molar teeth. Finally, the relative time and cost implications of the different approaches and materials, and the operator or technician’s ability to deliver high quality results with these options are also important considerations.

15.4 Choice of Materials 15.4.1 Cements Adhesive lutes can be used to cement a wide variety of restorative materials, from gold, semi-precious and non-precious alloys such as nickel-chrome or cobalt-­ chrome alloys, to an ever-increasing range of tooth-coloured materials. For metals, blasting the fit surface with 50  μm aluminium oxide (Al2O3) forms a roughened surface and an oxide layer on non-precious alloys and just a roughened surface on precious alloys for bonding with MDP primers which has been shown to produce a reliable bond [18], whilst the inclusion of VBATDT sulphur containing monomer in the primer further enhances the bond strength when precious alloys are used [19]. This is now a widely accepted technique. Heat treatment has also previously been recommended for the surface preparation of gold alloys to create an oxide layer for bonding. Blasting with aluminium oxide has the advantage of avoiding discolouration of the alloy, although this change in colour may not be permanent. This may be more practical as the oxide layer can be refreshed chair-side after try-in, using an intra-oral/chair-side blaster prior to cementation.

200

S. Watkins et al.

15.4.2 Restorative Materials A frequent problem encountered in the restoration of tooth wear is that of a lack of space for restorative materials, as well as occlusal loading in patients where attrition is a significant component in the aetiology. In these patients, tooth-coloured materials have often not performed well and metal restorative materials could be considered to be more predictable due to the fact that they are not prone to fracture and are strong in thin section. However, there are obviously aesthetic concerns in relation to metal restorative options and this continues to drive the development of the physical properties of tooth-coloured materials. There is limited data to support the use of specific materials or techniques in generalised tooth wear [20]. Of the few studies available, one has compared the use of indirect materials with resin composites in cases of severe generalised tooth wear, with survival rates of 74.5% and 62% respectively reported at 10 years [16]. This difference was not calculated to be statistically significant. Furthermore, biological failures were more highly associated with indirect restorations whilst mechanical failures were more often associated with composite resin. These latter failures were recognised as being more straightforward to manage and amenable to repair [14]. Gold restorations were associated with the least failures overall but are acknowledged to be less appropriate where aesthetics is a concern. In a more recent study, low failure rates have also been reported following the use of direct hybrid composites for managing patients with generalised tooth wear [21]. The emphasis in this chapter is on the application of various techniques rather than any specific materials, since the latter change constantly as developments are made. However, various options and their applications for restoring worn teeth with conventionally prepared teeth and cemented indirect restorations are covered in more depth in Chap. 16. The materials considered here are only those retained by adhesive principles.

15.4.2.1 Direct Composite Resin As with all composite resin materials, good isolation, such as that achieved with rubber dam, is essential to achieve a high quality and lasting result. The restorations may be built up free-hand (Fig. 15.17), assuming the operator has the anatomical knowledge and skills to do so. Alternatively, study casts and a diagnostic wax-up can be used to create a clear silicone key to “stamp” the composite restoration. On the surface, this technique appears very appealing. However, the operator should be aware of a number of pitfalls; firstly, achieving an anatomically convex proximal contact point is not possible with this technique, so oral hygiene will be compromised, with the ensuing risk of caries and periodontal issues. Secondly, the silicone key requires a support tooth either side to allow this to be accurately located, meaning that each tooth being restored will require a separate key; this requires a complex, staged diagnostic wax-up. A technique whereby the silicone matrix is used in conjunction with an injectable composite resin is also gaining in popularity and can produce good results (Fig. 15.18), although anatomical contact areas may be difficult to achieve and the long-term wear characteristics of these materials is unclear.

15  Adhesive Restorations

201

a

b

Fig. 15.17 (a) Pre-treatment and (b) post-treatment showing direct composite resin onlays restoring mandibular molars

a

b

c

e

d

f

Fig. 15.18 (a–f) Injectable technique for direct composite resin restoration

15.4.2.2 I ndirect Composite Resin Occlusal Onlays and Palatal Veneers This option removes some of the technical issues associated with direct composite onlays (Figs. 15.17 and 15.18). However, the technique is not without its own challenges. Firstly, worn teeth maintain contact in the proximal area. In order to create individual dies, these contact areas must either be opened prior to impressions, risking drift during the interim period whilst the restorations are made in the laboratory, or be separated in the laboratory with ensuing information loss. Both scenarios tend

202

S. Watkins et al.

to lead to sub-optimal contact points in the final restorations. Placing small sections of celluloid matrix strips into the contact points prior to impression taking can avoid this problem (Fig. 15.19). The next issue with cementing indirect composite resin is that the material is extensively cross-linked and does not readily form bonds with the composite luting material. This may be partially overcome by using composite primers to reactivate the fit surface. Another often overlooked shortcoming of indirect composite onlays is that, like all indirect restorations, they must have a path of insertion which may limit the available bonding surface area compared with a direct approach. This should be borne in mind when planning restorations, and undercuts may need to be adjusted or blocked out prior to impression making.

15.4.2.3 Adhesive Metal Onlays and Palatal Veneers In situations where occlusal forces are high and aesthetic demands are low, adhesive metal onlays provide an extremely durable restorative option (Fig. 15.20). These may be in a gold alloy or a non-precious alloy, with the latter being rather more abrasive against the opposing teeth but having the advantage of forming a natural oxide layer for bonding to luting materials containing MDP after blasting the fit a

b

Fig. 15.19 (a and b) Mylar strips placed inter-dentally prior to impression taking allows individual dies to be produced in the laboratory

a

b

Fig. 15.20 (a and b) Adhesive gold onlays in combination with direct composite onlays

15  Adhesive Restorations

203

Fig. 15.21  Ceramic onlay and preparation

surface with aluminium oxide (Al2O3). Less restorative space is required for metals than for ceramic or composite resin materials and they are not prone to bulk fracture, so this is another reason why they are a sensible choice for restoring molar teeth, since opening the vertical dimension provides less space the closer you are to the condyles.

15.4.2.4 Ceramic Onlays and Palatal Veneers Ceramic is by its nature a brittle material and so not naturally suited to areas of high lateral occlusal loading. For this reason, its use should be limited to those cases with robust anterior guidance on anterior teeth and low occlusal loads. Though zirconia has the highest flexural strength of all the dental ceramics, it cannot be etched or silanated and so requires conventional resistance and retention form. However, lithium disilicate can be etched and silanated and is therefore preferable where ceramic is desirable but intended to be purely adhesively retained (Fig. 15.21). Lithium disilicate requires around 2 mm thickness in load bearing areas which may be difficult to find in molar regions, even when an increased OVD is planned without tooth reduction.

15.5 Clinical Guides The following guides on selected techniques described above are intended as a chairside check-list for dental professionals new to managing anterior tooth wear with adhesive techniques.

15.5.1 Restoration of Anterior Tooth Wear with Direct Composite Resin Build-Up at an Increased OVD (Composite ‘Dahl’) • Prepare study casts and diagnostic wax-up (Fig. 15.22a). • Intra-oral ‘mock-up’ using bis-acryl temporary crown material in a silicone putty carrier to confirm that the wax-up reflects the desired outcome (Fig. 15.24).

204

a

S. Watkins et al.

b

Fig. 15.22 (a and b) Putty matrix for direct anterior composite restorations made from the diagnostic wax-up

• Fabrication of putty matrix (Fig. 15.22a, b) as a guide to the planned final contour, based on the diagnostic wax-up (Fig. 15.22a) and trimmed to allow seating to accommodate rubber dam where appropriate; extended to at least half a unit beyond the last tooth to be built up to ensure accurate seating on a tooth that has not been modified on the waxed model. It is helpful to trim to a 90-degree angle to the occlusal surface of the reference tooth, so that correct seating can be checked by direct vision. • Check fit of matrix clinically and ensure full seating; trim matrix and modify if necessary to achieve full seating. • If minimal tooth preparation is required, smooth any sharp enamel edges and consider a bevel to allow blending of composite at the labial junction for aesthetics. An intra-oral blaster with 50 μm aluminium oxide (Al2O3) is useful to remove calculus, pellicle, old restorations remnants and increase retention for bonding. • Preparation of the bonding surface following manufacturer’s instructions for bonding agent, with appropriate moisture control throughout. • Adapt a thin layer of composite resin to the palatal portion of the matrix of the tooth to be built up. If adjacent teeth are being built up, care must be taken not to link the teeth by using an inter-proximal matrix such as PTFE tape. If this does occur, metal inter-proximal polishing strips are useful to resolve this without opening the proximal contacts excessively. • Seat the matrix firmly in place and use a brush or probe to ensure the palatal composite is closely adapted to the area of tooth it contacts. • Cure first increment from labial aspect while keeping matrix in position. Do not remove the matrix. Repeat until all palatal aspects of the restorations have been completed. • Using suitable curved sectional proximal matrices add small increments of the ‘enamel’ shade composite resin to form the inter-proximal contact areas. • Build composite resin incrementally from the labial aspect. A layered approach allows good aesthetics to be achieved by utilising successive increments of ‘dentine’, ‘enamel’ and ‘translucent’ composite shades. • When the bulk of the build-up is complete, refine margins, proximal contacts and occlusion to ensure even ICP contacts on all teeth that have been built up with smooth, evenly distributed guidance.

15  Adhesive Restorations

205

• Complete shaping and finishing. • Note which teeth have been taken out of occlusal contact so that this can be monitored at subsequent reviews. • At review, check occlusion, including monitoring re-establishment of the posterior occlusion.

15.5.2 Restoration of Anterior Tooth Wear with Adhesively-­Retained Gold Alloy Palatal Veneers— With or Without Extending Incisal Length In the clinical setting—preparation of records • Minimal tooth preparation: smoothing of any sharp edges such as at the incisal edges. As metal can be finished to a feather edge margin, there is no need to prepare peripheral margins. • Records to include a full arch master elastomeric impression (Fig. 15.19b) or a digital scan (Fig.  15.23a) and an opposing arch elastomeric or alginate

a

c

d

b

Fig. 15.23 (a–d) Digital laboratory stages: scans and planning of restorations for diagnostic wax­up to full contour for construction of palatal veneers allowing space for addition of direct composite at fit, using backing as matrix for chair-side restoration. (a) Screen shot of working model for fabrication of gold palatal veneers. (b and c) Digital wax-ups showing increase in incisal length and diagnostic wax-up and manipulated to show backings and proposed composite addition finished result. (d) Digital wax-up—palatal view

206

S. Watkins et al.

impression or a digital scan, a facebow record and an appropriate inter-occlusal record. For the impressions, consider gingival retraction for the surfaces being restored to ensure that the maximum extent of tooth structure is recorded beyond the margin of the worn tooth surface to be restored. It is important to avoid drags at the margins as this prevents the laboratory distinguishing between the drag artefact and the recorded tooth structure. In the laboratory—diagnostic phase • If an increase in incisal length is planned: –– A diagnostic wax-up of the final contour is undertaken in the laboratory and this is used to construct metal palatal veneers incorporating the new contour within the design (Figs. 15.23b–d). –– It is important that a substantial part of the remaining palatal tooth contour remains unaltered during the process of creating this diagnostic wax-up, so that there is sufficient unmodified tooth structure for accurate seating of the palatal veneer and there is space for an opaque layer and enough composite resin to be applied after the veneer has been placed, to mask both the metal and opaquer, resulting in a natural shade to match the remaining tooth for a good aesthetic result (Figs. 15.23 and 15.25). –– This should be undertaken using accurate verified study casts mounted on a semi-adjustable articulator at an increased OVD with the aid of a facebow and retruded records, to allow analysis of occlusal space required and diagnostic waxing carried out at this OVD. In the clinical setting—try-in of mock-up if an increase in incisal length is planned • A putty index of the wax-up (Figs. 15.22, 15.23d, and 15.24b) can then be used to carry out an intra-oral ‘mock-up’ in bis-acryl temporary crown material (Fig. 15.24c) as described earlier (not to be given to the patient to take away due to risk of inhalation risk). In the laboratory • If no alterations are planned to the incisal length or if the incisal edges have already been lengthened with the addition of composite resin: the gold palatal veneers can be constructed to conform to the existing palatal contour (Fig. 15.10a– c), of the worn teeth by way of protection and to incorporate the maximum area for adhesive bonding, and extended over the incisal edge to protect the cement lute from shear forces and to assist in seating. • If an increase in incisal length is planned: the gold palatal veneers are constructed on the master working cast to fit the modified tooth contour, extending over the planned incisal edge, as illustrated (Fig. 15.25). The fit surfaces of the restorations are blasted with 50 μm aluminium oxide (Al2O3) powder to create an oxide layer for bonding.

15  Adhesive Restorations Fig. 15.24 (a–c) The use of wax-up to create an intra-oral mock-up in temporary crown material

207

a

b

c

a

b

c

Fig. 15.25 (a–c) Restoration design showing space for addition of composite resin and screen shot of backings prior to printing

• Table 15.1 shows an example of the laboratory request In the clinical setting—try-in and fit • Try-in of the gold palatal veneers: check for accuracy of fit and stability of seating and correct incisal extension. • Blast the fit surface with 50 μm aluminium oxide (Al2O3) prior to cementation. • Isolate the teeth as appropriate and cement veneers using an appropriate opaque luting cement following manufacturers’ instructions. • If an alteration to incisal length has been planned: –– the gold surface that is not contacting the tooth but is to be covered with direct composite to extend the incisal length subsequently can be covered with an opaque layer in the laboratory or by extending the opaque luting cement at cementation so that the gold is masked when the composite resin is placed (Fig. 15.26a, b). –– restore the remaining tooth structure with direct composite resin using a conventional incremental technique: a sufficient thickness of dentine shade

208

S. Watkins et al.

Table 15.1  Example of laboratory prescription for gold palatal veneers 1. Please pour maxillary and mandibular impressions 2. Mount the maxillary cast with the facebow record provided and the mandibular cast in the retruded position using the inter-occlusal record provided 3. Then please wax and cast gold palatal veneers for the maxillary anterior teeth extending the metal over the entire palatal aspects of the teeth and ½ way over incisal edge as in diagram ** 4. Feather edge margins, high in occlusion if necessary    Thank you **Where an increase in incisal length is to be incorporated, include the following: ‘Please wax-up the incisal edges of the maxillary anterior teeth to new planned contour (as determined by previous diagnostic wax-up) before constructing gold palatal veneers in order to incorporate space for composite resin addition at fit (see diagram below)’

Wax up to planned full contour

Extend metal backing to ½ way over planned incisal edge (feather edge finish) Composite and opaquer will be added at fit, as per wax up

a

b

Fig. 15.26  (a and b) Gold palatal veneers with opaque resin cement clearly visible masking the gold extensions prior to the addition of composite resin

composite is usually required to mask the opaque cement layer before any more translucent enamel is placed (Fig. 15.27a, b). • After cementation, check the occlusal contacts—ideally, these should be evenly distributed across all the palatal restorations, with the remaining teeth out of occlusal contact where a localised increase in vertical dimension was planned.

15  Adhesive Restorations

a

209

b

Fig. 15.27 (a and b) Pre-operative labial view and post-operative labial view with composite resin added

The patient may require reassurance that this will feel unusual initially but that it is expected that the tooth positions will alter so that contact between the posterior teeth will re-establish in the subsequent weeks and/or months, and that this will be monitored at review appointments. Record which teeth have are in/out of contact for future reference. • Final adjustments, detailing and finishing/removal of excess cement should be limited to avoid unnecessary vibration and heating of the immature cement lute and carried out at subsequent review appointments. In the clinical setting at review • Remove excess luting cement and undertake further finishing and fine polishing of composite resin restorations as necessary. • Check occlusal contacts and whether posterior tooth contacts have been re-established. –– If alveolar compensation has not yet occurred, this should be kept under regular review. –– If no noticeable improvement has occurred after 9–12 months, consideration must be given to placing occlusal restorations on the posterior teeth as described in the Sect. 3.5.3, conforming to the new occlusal vertical dimensions and occlusal scheme as defined by the palatal veneers.

15.6 Conclusion This chapter provides an overview of the current materials and techniques available to restore worn teeth using direct and indirect adhesive restorations. The techniques included are not an exhaustive list but are considered highly appropriate for managing tooth wear and are amongst the most evidence-based in dentistry. Given the ongoing developments in this field, the authors advise keeping up-to-date in this rapidly evolving area of clinical dentistry. Acknowledgements  With grateful thanks to the following:

210

S. Watkins et al.

• Dr Zohaib Ali for permission to use the clinical images in Figs. 15.7c, 15.26 and 15.27 • Mr Paul Byford for permission to use the digital laboratory images in Figs.  15.15, 15.23 and 15.25 • Dr Akit Patel for permission to use the clinical images in Fig. 15.16 • Dr Kostas Karagiannopolous for permission to use the clinical images in Fig. 15.18 • Dr Mo Al’Dashti for permission to use the clinical images in Figs. 15.19 and 15.20

References 1. Buonocore MG.  A simple method of increasing the adhesion of acrylic filling materials to enamel surface. J Dent Res. 1955;34(6):848–53. 2. Nakabayashi N, Kohima K, Masuhara E.  The promotion of adhesion by the infiltration of monomers into tooth substances. Biomed Mater Res. 1982;16:265–73. 3. Dahl BL, Krogstad O, Karlsen K. An alternative treatment in cases with advanced localised attrition. J Oral Rehab. 1975;2(3):209–14. 4. Hemmings KW, Darbar UR, Vaughan S. Tooth wear treated with direct composite restorations at an increased vertical dimension: results at 30 months. J Pros Dent. 2000;83(3):287–93. 5. Carlsson G, Ingervall B, Kocak G. Effect of increasing vertical dimension on the masticatory system in subjects with natural teeth. J Prosthet Dent. 1979;41:284–9. 6. Rivera-Morales W, Mohl N. Relationship of occlusal vertical dimension to the health of the masticatory system. J Prosthet Dent. 1991;65:547–53. 7. Hemmings KW, Truman A, Shah S, Chauhan R. Tooth wear guidelines for the BSRD Part 1: Aetiology, diagnosis and prevention. Dent Update. 2018;45:3–10. 8. Nohl FS, King PA, Harley KE, Ibbetson RJ. Retrospective survey of resin-retained cast-metal palatal veneers for the treatment of anterior palatal tooth wear. Quintessence Int. 1997;28:7–14. 9. Chana H, Kelleher M, Briggs P, Hooper R.  Clinical evaluation of resin-bonded gold alloy veneers. J Prosthet Dent. 2000;83:294–300. 10. Gulati JS, Tabiat-Pour S, Watkins S, Banerjee A. Resin-bonded bridges—the problem or the solution? Part 2: Practical techniques. Dental Update. 2016;43(7):608–10. 613–6 11. Redman CDJ, Hemmings KW, Good JA.  The survival and clinical performance of resin–based composite restorations used to treat localised anterior tooth wear. Br Dent J. 2003;194(10):566–72. 12. Poyser NJ, Briggs PF, Chana HS, Kelleher MG, Porter RW, Patel MM. The evaluation of direct composite restorations for the worn mandibular anterior dentition—clinical performance and patient satisfaction. J Oral Rehabil. 2007;34:361–76. 13. Milosevic A, Burnside G.  The survival of direct composite restorations in the management of severe tooth wear including attrition and erosion; a prospective 8 year study. J Dent. 2016;44:13–9. 14. Varma S, Prieskel A, Bartlett D.  The management of tooth wear with crowns and indirect restorations. Br Dent J. 2018;224(5):343–7. 15. Gulamali AB, Hemmings KW, Tredwin CJ, Petrie A.  Survival analysis of composite Dahl restorations provided to manage localised anterior tooth wear (ten year follow-up). Br Dent J. 2011;211(4):E9. 16. Smales RK, Berekally TL. Long-term survival of direct and indirect restorations placed for the treatment of advanced tooth wear. Eur J Prosthodont Rest Dent. 2007;15(1):2–6. 17. Eliyas S, Martin N.  The management of anterior tooth wear using gold palatal veneers in canine guidance. Br Dent J. 2013;214:291–7. 18. Shafei F, et al. Bond Strength of self-adhesive resin cement to base metal alloys having different surface treatment. Dent Res. 2018;15(1):63–70. 19. Yoshida K. Effect of sulphur-containing primers for noble metals on the bond strength of self cured acrylic Resin. Dent J. 2017;5(2):22.

15  Adhesive Restorations

211

20. O’Sullivan E, Toor I, Brown L, Watkins S. Clinical guideline for dental erosion. Diagnosis, prevention and management of dental erosion 2021. Faculty of Dental Surgery, Royal College of Surgeons of England, London, 2021. 21. Hamburger JT, Opdam NJ, Bronckhorst EM, Kreulen CM, Roeters JJ, Husymans MC. Clinical performance of direct composite restorations for treatment of severe tooth wear. J Adhes Dent. 2011;13:585–93.

Fixed Prosthodontics

16

Konstantina Dina Dedi

16.1 Introduction When patients present seeking help for functional or aesthetic problems, the primary reasons may not be limited to tooth decay or fractured teeth. Often, the underlying causative factor may be ongoing mechanical forces, sometimes compounded by erosion, that eventually alter the anatomy of the teeth and the inter-occlusal space leading to sensitivity, pulpal necrosis and failure of restorations. As a result, predictable restoration of teeth whilst re-establishing function and aesthetics for patients with tooth wear caused by parafunctional activity and erosion can be incredibly challenging and complex. The incisal edges of the anterior teeth often become thin, flat and irregular (Fig. 16.1) and patients may complain of their posterior teeth chipping and breaking despite repeated repairs. Those patients who are aware of grinding and clenching habits as a possible contributory factor may also complain of temporomandibular dysfunction (TMD). Others may notice that their teeth are no longer as visible during speaking or smiling, or that the colour of their teeth has gradually darkened, with yellow or brown areas especially near the soft tissue margins. As just one example of how tooth shape may be influenced in patients with a deep overbite, the mandibular anterior teeth might occlude near the soft tissues palatal to the maxillary anterior teeth, overloading them unfavourably and creating step-like tooth wear (Fig. 16.2). With prolonged tooth wear, the mandibular anterior teeth may lose substantial volume from their incisal and buccal surfaces (Fig. 16.3), exposing dentine and even pulp chambers, eventually becoming devitalised and necrotic. Usually, the loss of tooth structure indicates ongoing destructive activity that may continue even after

K. D. Dedi (*) UCL Eastman Dental Institute and Harley Street Dental and Implant Clinic, London, UK e-mail: [email protected] © Springer Nature Switzerland AG 2022 A. Eder, M. Faigenblum (eds.), Tooth Wear, BDJ Clinician’s Guides, https://doi.org/10.1007/978-3-030-86110-0_16

213

214

K. D. Dedi

Fig. 16.1  Chipped and irregular incisal edges and abrasions or abfractions near the gums of the maxillary right central and lateral incisors

Fig. 16.2  Palatal tooth wear created by the incisal edges of the mandibular anterior teeth

Fig. 16.3 Worn mandibular anterior teeth and disrupted occlusal planes

new restorations have been provided. A comprehensive risk assessment (Chap. 3) must be undertaken, and any restorative care plan needs to consider the amount of remaining tooth for each tooth, the occlusal planes and scheme, any available space for restorative materials, required clearance between tooth preparations and the opposing dentition as well as the location of the pulp chambers and the soft tissues.

16  Fixed Prosthodontics

215

16.2 Effects of Tooth Wear Many patients who present with tooth wear may not even be aware they have a problem. Despite this, considerable structural changes may have already taken place affecting the anatomy, vitality, shape and function of the teeth. Anterior teeth may shorten, incisal edges may flatten, incisal embrasures become less distinct and palatal surfaces may lose the characteristic s-shape of the cingulum areas, becoming more concave (Fig. 16.4), while buccal surfaces are subject to ongoing enamel loss. This loss of volume from anterior teeth compromises their rigidity and strength. It increases their flexure upon loading, making them weaker and more prone to fracture. When anterior teeth are prepared to receive conventionally retained crowns, the retentive and resistive form of the preparation relies on adequate palatal volume (Fig. 16.5). On a severely eroded or worn anterior tooth, this preparation form may be compromised due to the wear (Fig. 16.6). Interestingly, the horizontal cross-section of an anterior aged and worn incisor tooth has an oval buccal outline in comparison to an unworn tooth which has a squarer, and more robust, outline. This indicates that there is usually extra enamel loss from the proximal line angles resulting in inter-dental contact points which become broader and tighter contact areas. There is also a trend of tooth migration toward the midline increasing anterior crowding. Posterior teeth become shorter and flatter losing cusp tips and cuspal inclinations. Working-side cusps are affected more severely. Occlusal tables become wider as cusp tips are worn and the contour height of the tooth migrates more apically (Fig. 16.7). Dentine may become exposed in some areas resulting in sensitivity and an increased risk of caries and pulpal problems (Chap. 6). In view of rigidity and flexural strength being compromised, worn teeth may become more prone to fracture initiation and propagation. At the same time, the integrity and longevity of teeth, and restorations, may be reduced. In addition to wear facets on teeth and indentations in the cheeks and to the lateral borders of the tongue, a characteristic sign of parafunction is the presence of non-carious lesions near the gum margins thought to be due to flexure. Referred to Fig. 16.4  Eroded concave palatal surfaces

216

K. D. Dedi

Fig. 16.5  Anterior crown preparation on a tooth with adequate palatal tooth volume

as ‘abfractions’, these are oval shaped defects that tend to deepen with rigorous tooth brushing accelerating dentinal loss. In the most severe situations, teeth become weaker and may even fracture at the gum level [1]. In patients where teeth have been lost and not replaced, unopposed teeth may over-erupt or tilt resulting in disruption of the occlusal planes. In such situations, the remaining teeth may no longer be functional or there may be a lack of space for tooth replacement to re-establish satisfactory function once again (Fig. 16.8). As a result, the functional and aesthetic challenges increase and the need for restorative care for the reduced number of remaining functional units may become far more complex (Fig. 16.9a–c).

16.3 Approaches to Managing Tooth Wear Previous chapters have addressed assessment, diagnosis, records and a broad range of options in terms of management (Chaps. 8, 9 and 10). This chapter focuses on fixed prosthodontic approaches which will normally involve tooth preparation and

16  Fixed Prosthodontics

217

Fig. 16.6  With palatal tooth wear (highlighted in red) on an anterior tooth, the design features for conventional crown preparation may be compromised

Fig. 16.7  Worn posterior teeth with wider occlusal tables and the mandibular right first molar prepared for an onlay-crown

may rely on conventional retention and resistance principles, perhaps with additional groves and slots, as well as adhesive concepts. In moderate cases of tooth wear, and subject to the clinical requirements, teeth can generally be restored on an individual tooth-by-tooth basis conforming to the existing occlusal relationships (Sect. 16.4). However, in more severe cases where

218

K. D. Dedi

Fig. 16.8 Disrupted occlusal plane with over-eruption of unopposed molars

a

b

c

Fig. 16.9 (a) Severe tooth wear clearly evident on smiling. (b) Labial view showing advanced tooth wear and disrupted occlusal planes with missing teeth in maxillary left and mandibular right posterior quadrants. (c) Severely worn teeth and disrupted occlusal planes in the left hand-side

multiple teeth may be involved, inter-occlusal space may be limited and the existing occlusal planes may be compromised, a rather more comprehensive—or reorganised—approach is recommended to establish a new synergistically functional dentition (Sects. 16.5 and 16.6). Regarding the initial patient assessment, one point must be highlighted. It is essential to identify evidence of occlusal parafunction and to share this with the patient as they may simply not be aware that they are grinding and clenching, and this can have a significant impact on professional management of what patients might otherwise consider as realistic expectations and can instead lead to early failure and disappointment.

16  Fixed Prosthodontics

219

The presence of wear facets, abfractions, flattening of incisal edges, bilateral linea alba and scalloping of the sides of the tongue should all be considered as warning signs which might suggest the presence of active parafunctional habits such as grinding or clenching. These additional biting loads introduce unfavourable oblique and lateral forces resulting in more tooth wear and temporomandibular problems as well as increased rates of fracture, restoration failure, pain and sensitivity. Patients need to be advised about the effects of grinding and clenching and to have realistic expectations regarding the longevity of their restorations.

16.4 M  anaging Localised Anterior Tooth Wear Conforming to the Existing Occlusal Vertical Dimension This 46-year-old male patient presented with concerns about the appearance of his worn anterior teeth (Fig. 16.10a, b). Having identified erosion and parafunction as aetiological factors and initiated preventive measures, study casts were mounted on a

b

c

d

e

Fig. 16.10 (a) Pre-operative labial view on smiling. (b) Pre-operative labial view in maximum intercuspation. (c) Anterior diagnostic wax-up. (d) Intra-oral mock-up at try-in. (e) Anterior teeth restored with ceramic veneers just after cementation

220

K. D. Dedi

a semi-adjustable articulator with the aid of a face-bow and retruded records. A diagnostic wax-up was prepared at the existing occlusal vertical dimension (OVD) to recreate missing tooth tissue from the buccal surfaces and incisal edges as well as re-establishing canine guidance which had been lost (Fig. 16.10c). The new shapes were tested intra-orally with a mock-up (Chap. 10) (Fig. 16.10d). Following minimal tooth preparation, anterior ceramic veneers were fabricated and bonded to the maxillary anterior teeth to restore the missing tooth volume and re-establish appearance and function. (Fig. 16.10e). The premolars were restored soon after.

16.5 Introducing the Dahl Concept In some patients, tooth wear may be far more localised and, as a result, only a selected number of teeth will need to be restored. For example, only the palatal surfaces of the maxillary anterior teeth may have been affected making them thin and concave (Fig. 16.11a). When the cingulum area loses its characteristic s-shape anatomy and becomes flat or concave, the occlusal forces on the maxillary anterior teeth are no longer transferred along their long axes and instead become more oblique which are far less favourable and potentially damaging. This situation is often seen in patients with tooth wear as a result of dietary erosion, gastro-­ oesophageal reflux disease or acid regurgitation in bulimic patients (Fig.  16.4) (Chap. 5). As a direct result of losing a substantial part of the palatal coronal volume, the anterior teeth can erupt toward one another and maintain contact resulting in an increased anterior overbite. If wear progresses significantly, the maxillary anterior teeth will, most likely, need restoration and reinforcement in the fullness of time. However, at that point, there may no longer be enough tooth structure remaining to prepare the teeth for conventionally retained restorations, particularly if tooth preparation is required to create space. When providing care in accordance with the Dahl concept [2], customised palatal veneers are cemented onto the palatal surfaces of the worn maxillary anterior teeth to replace the missing tooth tissue and re-establish normal tooth contour (Fig.  16.11b). The occlusion is then adjusted on the veneers until equal occlusal a

b

Fig. 16.11 (a) Maxillary anterior teeth isolated with rubber dam highlighting the worn palatal tooth surfaces prior to cementation of palatal veneers. (b) Indirect composite palatal veneers on working cast prior to cementation with orientation and positioning jigs over the incisal edges to be removed after cementation

16  Fixed Prosthodontics

221

contacts exist across all the anterior teeth at maximum intercuspation, normally at an increased OVD equal to the thickness of the palatal veneers, leaving the posterior teeth out of contact [2]. However, there is good evidence that the posterior occlusion will soon be re-­ established as the anterior teeth intrude due to the occlusal contacts and loading whilst the posterior teeth erupt toward one another. In support of this technique, the periodontal condition must be healthy and the load on the anterior teeth needs to be axial in direction. The intended movements will take longer in some patients than others and swifter movements are generally seen in younger patients where the eruptive potential is greater. This technique using definitive restorations as described is an extension of the original studies by Dahl which relied on a removable base metal palatal construction to act as an anterior bite-plane to create space prior to definitive restoration. Contemporary versions of the technique have used individual adhesively retained gold or non-precious alloys, etchable monolithic lithium disilicate or indirect composite resin as palatal veneers for definitive restorations. The technique can also be used as an interim situation, normally with direct or indirect composite resin, prior to the provision of definitive full coverage crowns once space has been created by reorganising the occlusion. Clinical steps are described in more detail in Chap. 15. In some cases, and instead of just using palatal veneers, the Dahl concept can be followed by extending the palatal veneers into laboratory fabricated provisional crowns for the anterior teeth with the palatal surfaces having been developed similarly with ideal anatomy increasing the OVD as planned [3]. This method also works well for posterior teeth. Figures 16.12a–d show a female patient with erosion and missing left maxillary molars. The mandibular first molar had erupted into contact with the opposing soft tissue (Fig. 16.12a). A temporary non-precious alloy bridge placed these teeth in contact at an increased OVD (Fig. 16.12b). As intrusion occurred, composite resin was added to maintain supra-­ occlusion until the mandibular occlusal plane was corrected (Fig. 16.12c). The final bridge is shown in Fig.  16.12d, intrusion of the upper abutments eliminating the need for occlusal reduction. Follow up over ten years confirmed no adverse consequences for any of the teeth involved in treatment.

16.6 M  anaging Localised Anterior Tooth Wear Using the Dahl Concept to Create Space The Dahl concept can also be used to create space prior to definitive restoration. A 40-year-old female patient presented with multiple failing restorations, short anterior clinical crown height, localised palatal wear of the anterior teeth and evidence of parafunctional activity. Moreover, she was not happy with her ‘gums showing too much’ on smiling (Fig. 16.13a). The maxillary anterior teeth were too thin to be prepared for crowns with sufficient retention and resistance form and there was insufficient enamel present for predictability with ¾ adhesive veneer restorations.

222

K. D. Dedi

a

b

c

d

Fig. 16.12 (a) Over-erupted mandibular molar. (b) Temporary non-precious alloy bridge in maxillary arch. (c) Corrected mandibular occlusal plane. (d) The final bridge

The current occlusal scheme was also unfavourable with regard to fatigue loading of the front teeth (Fig. 16.13b). Study casts were mounted on a semi-adjustable articulator with the aid of a face-­ bow and retruded records for diagnostic purposes (Chap. 10). Indirect composite resin palatal veneers with a thickness of 1 mm were fabricated in the laboratory. These were fitted at an increased OVD in accordance with the Dahl concept to create the necessary space, volume and contours prior to preparing the teeth for crowns and, at the same time, rearranging the occlusion to a more optimal occlusal plane (Fig. 16.13c). Once posterior contacts were re-established, new study casts were mounted on a semi-adjustable articulator with the aid of a face-bow and retruded records (Chap. 10) and an anterior diagnostic wax-up was completed (Fig. 16.13d). This was transferred into an intra-oral mock-up (Chap. 10) which was tried into the patient’s mouth in the clinical setting for assessment and feedback (Fig. 16.13e). It was determined that crown lengthening surgery was required to reduce the amount of soft tissue showing when smiling and to increase the length of the anterior teeth (Chap. 13). Provisional crowns were provided after three months and definitive crowns were fitted after a further 3 months (Fig. 16.13f, g).

16  Fixed Prosthodontics

223

a

b

c

d

e

f

g

Fig. 16.13 (a) Pre-treatment view on smiling. (b) Pre-treatment view of the anterior teeth in the inter-cuspal position. (c) Anterior view after anterior palatal veneers fitted at an increased OVD. (d) Maxillary anterior diagnostic wax-up. (e) Mock-up from wax-up transferred intra-orally for assessment and feedback. (f) Post-treatment view on smiling. (g) Post-treatment view immediately after crowns fitted

16.7 M  anaging Generalised Full Mouth Tooth Wear at an Increased Occlusal Vertical Dimension A 58-year-old female patient presented with generalised tooth wear following a long history of parafunction compounded by significant levels of dietary acids from fruit, fruit juice and carbonated drinks. The patient was not aware of any

224

K. D. Dedi

gastro-­oesophageal reflux. Little natural tooth showed on smiling and composite resin additions to the maxillary incisal edges kept failing. The teeth had lost considerable amounts of enamel leaving areas of exposed dentine and a reduction in OVD with hardly any of the normal lip fullness showing (Fig. 16.14a, c, e, g, i and k). Initial care priorities addressed the aetiology, introduced preventive measures and ensured stability. This patient needed extensive restorative care which can appear daunting in terms of planning, execution, temporisation and definitive restoration. Paradoxically, some of the basic principles mirror aspects in the provision of complete dentures. In both clinical scenarios, there is a need to re-establish anterior aesthetics and lip support as well as a functional occlusion at a comfortable and appropriate, most probably increased, OVD working in harmony with the neuromuscular structures and the temporomandibular joints. For restorative convenience, the retruded position is most likely to be selected as a reproducible reference point replacing the existing inter-cuspal relationship. Having completed the initial assessments, as well as radiographic and clinical evaluations, study casts were mounted on a semi-adjustable articulator with the aid of a face-bow and retruded records (Chap. 10). A numerical functional assessment of the existing freeway space was determined clinically. The difference between this number and the average free-way space of 2–3 mm was recorded and this became the intended increase of the OVD between the anterior teeth. A full mouth diagnostic wax-up was then developed, starting with the maxillary anterior teeth, ideally with the help of any available photographs showing the face and teeth before the wear resulted in shorter teeth and a reduced OVD. Instructions to the technician included the desired tooth shapes (square, tapered, or square-­ tapered) and length, the character of incisal embrasures, the amount of texture and the incisal tooth position. A tentative length can be initially calculated with the width to length equation according to Magne et al. [4]. At this point, an intra-oral mock-up is helpful to confirm aesthetics, lip support and speech as well as any modifications that may be required (Chap. 10). A mock­up is created from the diagnostic wax-up by transferring the shapes into a suitable temporary material or by digitally producing from a 3D model. This mock-up can then be tried in the mouth over the existing teeth in the clinical setting for assessment and feedback [5]. Once the shapes and contours of the maxillary anterior teeth have been confirmed, this helps to inform any changes to the diagnostic wax-up that may be required, and the mandibular anterior teeth can then be refined. The posterior mandibular teeth, followed by the posterior maxillary teeth, can then be finalised taking into account appropriate occlusal considerations. The new occlusal scheme should aim to provide posterior stability, anterior guidance (canine protected) and no non-­ working side interferences. For this patient, surgical crown lengthening of multiple teeth was required to increase the coronal height of teeth that were to be prepared so that they could predictably support the planned crown restorations (Chap. 13). A surgical guide was

16  Fixed Prosthodontics

225

a

b

c

d

e

f

g

h

i

j

Fig. 16.14 (a) Pre-treatment teeth together. (b) Post-treatment teeth together. (c) Pre-treatment relaxed smile. (d) Post-treatment relaxed smile. (e) Pre-treatment teeth together. (f) Post-treatment teeth together. (g) Pre-treatment teeth apart. (h) Post-treatment teeth apart. (i) Pre-treatment maxillary occlusal. (j) Post-treatment maxillary occlusal. (k) Pre-treatment mandibular occlusal. (l) Post-treatment mandibular occlusal. (m) Post-treatment occlusion in right. (n) Post-treatment occlusion in left. (o) Post-treatment Michigan Splint over maxillary teeth for night wear

226

k

m

K. D. Dedi

l

n

o

Fig. 16.14 (continued)

fabricated based on the diagnostic wax-up to assist in achieving the intended crown height and gingival margin position. Following healing, the diagnostic wax-up was refined further and silicone matrices produced for groups of teeth copying the diagnostic wax-up. These matrices were used to build up the existing teeth with core fillings to facilitate appropriate reduction and preparation of the teeth for full coverage restorations. Provisional restorations, also made based on the diagnostic wax-up, provide a shared opportunity to evaluate the new lip support, OVD (which may also have been tested with a Michigan Splint at the outset) and tooth design intra-orally. This allows for any adjustments to be made prior to definitive restorations being made and fitted (Fig.  16.14b, d, f, h, j, l, m and n) which reflect the confirmed provisional restorations. As part of securing informed consent (Chap. 8), patients must be made aware at the outset of the adverse nature of ongoing parafunctional activity that will most likely still exist following treatment as this could lead to early failure. To this end, a

16  Fixed Prosthodontics

227

Michigan Splint should be worn overnight for protection (Fig. 16.14o) to hopefully delay the effects of any future destructive parafunctional forces on the teeth and restorations (Chap. 11).

16.8 M  aterials and Designs for Fixed Prosthodontics in the Management of Tooth Wear When designing fixed prosthodontic restorations for patients with tooth wear, the availability or creation of space for restorative material needs to be planned carefully taking into account the required clearance with the opposing dentition, the amount of enamel remaining, the available coronal tooth height, the position of the pulp chamber and the evidence of parafunctional forces. Despite the need to remove even more tooth tissue, predictable options include full coverage crowns, either all gold posteriorly or gold-ceramic crowns anteriorly or posteriorly, with gold occluding surfaces when there is less than 2  mm inter-­ occlusal clearance required for ceramic, either on its own or overlaying gold. The gold occluding surface is not only strong in thin section but is also a more ‘forgiving’ surface which is not susceptible to crack propagation which is seen in ceramic surfaces. Gold occlusal surfaces are, therefore, a far more predictable solution in parafunctional patients, particularly where anterior and lateral guidance may be limited resulting in unfavourable oblique fatigue forces. A less invasive biomimetic approach not only replaces the missing enamel and dentine with ceramic partial onlay-crowns or full crowns using adhesive techniques but also aims to re-establish the ideal physical properties such as rigidity as just one example (Fig.  16.15). Although this conservative approach is becoming increasingly popular, it relies on the presence of peripheral enamel and effective isolation as well as strict adherence to adhesive protocols for bonding [6]. Whilst attractive in terms of preserving tooth tissue, there is an increased potential for sensitivity (Chap. 6) due to the use of resin adhesion on large areas of dentine. There is also an increased risk of restoration fracture if lithium disilicate is used, rather than metal or zirconia, in situations of limited occlusal space compounded by parafunctional activity. Fig. 16.15  Intra-oral view after cementation of a monolithic stained lithium disilicate crown on the mandibular right first molar. The second molar was restored soon after

228

K. D. Dedi

In recent years, an increase in aesthetic demands from both patients and dental professionals has led to an exponential growth in research and development of new technologies and materials for the application of tooth-coloured materials in the field of fixed prosthodontics. The latest zirconia materials have improved fatigue strength and increased translucency and can be used for crowns and bridges. These materials perform better in their monolithic form with bespoke staining rather than layering. Cementation is with a resin modified glass ionomer cement which forms a chemical bond with dentine and is not associated with post-cementation sensitivity [7]. When missing teeth are to be replaced with conventional fixed bridges in patients with tooth wear, care must be taken in assessing the potential abutment teeth particularly if they have differing levels of periodontal support and are likely to receive different amounts of occlusal loading based on their position in the arch. For patients with evidence of parafunctional activity, it is preferable to avoid long-span bridgework. Compounding this is flexure of the mandible making the area of the first molars particularly susceptible to bending moments resulting in an increased risk of decementation leading to caries and prosthodontic failure [8] (Chap. 19).

16.9 Conclusion Since the previous edition of this book, there has been a shift from conventional preparation fixed prosthodontics (a ‘subtractive’ approach) where even more healthy tooth tissue needs to be removed from already worn teeth to a far more pragmatic and minimum intervention approach reliant on adhesive dentistry (an ‘additive’ approach) which has seen tremendous developments over the past 20 years. The results of this shift are such that it is no longer justifiable to run the risk of preparing already worn teeth and sacrificing crown height that is required for retention and resistance to obtain inter-occlusal space when it is readily available by other means. Moreover, and taking into account one or more of surgical crown lengthening, reorganising of the occlusion and adhesive dentistry, it is no longer a common procedure to electively devitalise teeth so that post and core restorations can be placed to extend short clinical crowns. However, conventional fixed prosthodontics still has a place in the management of patients with tooth wear, particularly where teeth are already heavily restored or when adhesive dentistry is not a predictable option, as highlighted in this chapter. Acknowledgements  Professor Derrick Setchell for permission to use the clinical images kindly allowing inclusion of the case shown in Fig. 16.12a–d. • Mrs. Caroline Brill for permission to use the clinical images in Fig. 16.14, to Professor Andrew Eder for providing the restorative care, to Dr. Richard Tucker for providing the periodontal care and to Richard Gidden, Dental Technician, for providing laboratory and technical support.

16  Fixed Prosthodontics

229

References 1. Sarode GS, Sarode SC. Abfractions: a review. J Oral Maxillofac Pathol. 2013;17(2):222–7. 2. Dahl BL, Krogstad O, Karlsen K. An alternative treatment in cases with advanced localized attrition. J Oral Rehabil. 1975;2(3):209–14. 3. Magne P, Magne M, Belser U. Adhesive restorations, centric relation, and the Dahl principle: minimally invasive approaches to localized anterior tooth erosion. Eur J Esthet Dent Autumn. 2007;2(3):260–73. 4. Magne P, Gallucci G, Belser U. Anatomic crown width/length ratios of unworn and worn maxillary teeth in white subjects. J Prosthet Dent. 2003;89(5):453–61. 5. Sancho-Puchades M, Fehmer V, Hämmerle C, Sailer I.  Advanced smile diagnostics using CAD/CAM mock-ups. Int. J Esthet Dent. 2015;10(3):374–91. 6. Grütter L, Vailati F.  Full-mouth adhesive rehabilitation in case of severe dental erosion, a minimally invasive approach following the 3-step technique. Eur J Esthet Dent Autumn. 2013;8(3):358–75. 7. Fehmer V, Mühlemann S, Hämmerle CH, Sailer I. Criteria for the selection of restoration materials. Quintessence Int. 2014;45(9):723–30. 8. Scurria MS, Bader JD, Shugars DA. Meta-analysis of fixed partial denture survival: prostheses and abutments. J Prosthet Dent. 1998;79(4):449–64.

Removable Prosthodontics

17

Kenneth Hemmings

17.1 Introduction Severe wear, particularly when coupled with tooth loss, can produce marked changes in the occlusion and a significant aesthetic deficit. A removable prosthesis may be the appropriate restorative approach particularly when wear is advanced. Determination of the correct vertical dimension for the occlusion and an appropriate jaw relationship form the basis of treatment whether this employs fixed or removable prostheses. Removable prostheses can be used alone or in combination with fixed prosthodontic treatment to manage tooth wear to restore appearance and function [1, 2]. The lack of coronal tooth structure in cases of severe tooth wear can make fixed prosthodontic treatment unpredictable favouring a removable approach which may be more cost effective and have a shorter treatment time. The remaining coronal tooth tissue can be used to support, retain, and/or stabilise a removable prosthesis. Nevertheless, patients will need to be made aware of the limitations associated with removable appliances including the added maintenance and potential risks to the remaining dentition if compliance is poor.

17.1.1 Indications for Removable Management of Tooth Wear • • • • • •

Severe wear Multiple missing teeth and tooth wear Soft tissue defects Long spans or distal extension Tooth wear in a patient well adapted to wearing partial dentures Primary disease not controlled or uncertainty with the prognosis of some teeth

K. Hemmings (*) UCLH Eastman Dental Hospital and UCL Eastman Dental Institute, London, UK e-mail: [email protected] © Springer Nature Switzerland AG 2022 A. Eder, M. Faigenblum (eds.), Tooth Wear, BDJ Clinician’s Guides, https://doi.org/10.1007/978-3-030-86110-0_17

231

232

K. Hemmings

17.1.2 Contra-Indications for Removable Management of Tooth Wear • Poor tolerance of a removable prosthesis

17.2 Compensated or Non-compensated Tooth Wear Restoring the worn dentition to the correct occlusal vertical dimension will form the basis of treatment. In the absence of tooth wear, the free-way space remains constant due to the continued growth and increase in anterior facial height into middle age [3, 4]. Tooth wear, however, leads to the continued eruption of teeth so that the free-way space remains constant and so do the proportions of the face. This is commonly known as compensated tooth wear [5, 6] Sicher supported this view and found that 80% of severe wear cases had a normal free-way space (i.e. 3 mm) [7]. However, there is a contrary view [4] which affirms that the free-way space is affected by wear and its magnitude is proportionate to the degree of attrition. There is a variation in presentation of severe tooth wear which is not always readily explained by changes in free-way space and occlusal vertical dimension [8, 9]. Non-compensated tooth wear occurs when the rate of the tooth wear is too fast for the physiological mechanisms of tooth eruption to keep up [10]. There is, therefore, a resultant increase in free-way space and loss of occlusal vertical dimension. From this respect two definitions of tooth wear exist: • Compensated tooth wear: Tooth wear without loss of occlusal vertical dimension and free-way space within normal limits usually in a complete or near complete dentition. • Non-compensated tooth wear: Tooth wear with loss of occlusal vertical dimension and a greater free-way space than normal, usually associated with a depleted dentition and a lack of posterior support. Stern and Brayer [11] state that ‘Pathological changes of the occlusion may occur when posterior support is reduced or lost’. In these cases, the mandible requires a new support which is usually found in the anterior region of the mouth. Consequently, any excessive occlusal load affects the anterior teeth. Such an event is known as ‘occlusal collapse’. Russell [10] supports this concept. He considers a free-way space in excess of 5–6 mm is abnormal and that the occlusal wear it has produced has occurred at a rate faster than the physiological mechanisms designed to compensate for it (Fig. 17.1). Patients with compensated tooth wear will usually have a complete dentition and treatment with removable prostheses will rarely be indicated [1]. Partially dentate patients with loss of the posterior dentition and wear affecting the anterior teeth will usually present with non-compensated tooth wear and a loss of occlusal vertical dimension making it necessary to provide treatment with removable prostheses. These patients will often have an unacceptable occlusal plane and the following can be used to determine the correct occlusal vertical dimension:

17  Removable Prosthodontics

a

233

b

Fig. 17.1  Non-compensated tooth wear in a depleted dentition. Clinical appearance (a) at rest and (b) with teeth in occlusion

17.3 Assessing the Occlusal Vertical Dimension The selection of the occlusal vertical dimension can be helped by considering the following: 1. The point of first contact along the retruded arc of closure if there are unworn teeth posterior to the worn anterior teeth. This will be the retruded contact position and may provide the required space to restore the worn anterior dentition. 2. Photographs of the patient’s teeth prior to becoming worn. 3. Tooth display at rest and on smiling. 4. Amount of posterior prosthetic space required if necessary. 5. Phonetics. 6. Use of a provisional denture for between 6 weeks and 6 months. After this period of time, the patient can give their approval that the appearance and function is satisfactory. The recording of the occlusal vertical dimension is usually carried out using occlusal registration rims. The final selection of the occlusal vertical dimension is usually confirmed in the dental laboratory. The above factors are taken into account together with space requirements for durable veneer/facings, onlays and overdenture components. It is rare for changes in the occlusal vertical dimension not to be tolerated if the denture is tooth and tissue borne.

17.4 Removable Management Not all severely worn teeth can be restored or repaired satisfactorily. When teeth have lost over half of their original crown height it may be more cost effective to reduce them further and build over them with a removable prosthesis. Similarly, if

234

K. Hemmings

there are a number of missing teeth and there is a need for soft tissue replacement a removable prosthesis may be more appropriate. They can also be designed to allow tooth additions in the future. Despite the benefits of removable prostheses, they can lead to increased levels of plaque accumulation when oral hygiene is inadequate [12]. It is, therefore, even more critical that patients are given clear instructions on maintaining excellent oral hygiene and advised to leave their removable prostheses out at night. Failure to do so may quickly lead to failure of strategic abutment teeth and further challenges for the patient and clinician. Patients need to have realistic expectations of removable appliances. Dentures for tooth wear have an increased bulk when compared to conventional partial dentures. They will be subject to high occlusal load and will require significantly more maintenance. Not all teeth need replacement. Depending on age and the absence of dental pathology patients can function well with 10 pairs of occluding units or a second premolar to second premolar occlusion [13, 14]. Patients presenting with severe tooth wear often do so because it affects their anterior teeth. A lack of posterior support may lead to the increase in wear of anterior teeth or failure of anterior restorations [15]. Compliance with removable prostheses has been shown to be better when they replace and/or restore the anterior dentition [16].

17.5 Treatment Options 17.5.1 Extracting the Remaining Teeth and Providing Complete Dentures This may be thought of as a simple option for dealing with tooth wear in a patient with a depleted dentition. However, patients have a greater life expectancy and are retaining teeth for longer [17]. The potential problem is that patients rendered edentulous at an older age have less adaptive capacity to manage complete dentures. As a result, dental clearances are provided less frequently and a longer transitional phase from partial to complete edentulism is experienced by most patients. It can still be a pragmatic option if few teeth remain and complex or expensive treatment considered inappropriate. Anecdotally, it is often thought that bruxist patients transform into maladaptive denture wearing patients because occlusal loads can lead to early mucosal trauma and ridge resorption. Great skill will be required to provide complete dentures for patients at this stage. An implant supported mandibular overdenture may be required to provide good function for such patients [18, 19]. Maintenance of the implant overdentures is likely to be high as elevated occlusal loads will remain.

17.5.2 Complete or Partial Overdentures When making dentures for patients with tooth wear, a decision has to be made whether to build on or over retained roots as overdenture abutments. Similarly, teeth

17  Removable Prosthodontics

235

which are worn with reduced clinical crown height that are not going to be restored to normal contour may have to be covered by the denture. The following options could be considered: 1. Overdenture: a denture that replaces the worn or missing teeth with prosthetic teeth and an acrylic flange (Fig. 17.2) 2. Onlay denture: covers the occlusal or incisal surfaces of the abutment teeth (Fig. 17.3) 3. Overlay denture: covers the worn teeth with a full labial veneer facing (Fig. 17.4) Combinations of the above can be used on the same prosthesis [20] and a standard design system should be used to include: (a) saddles (b) support (c) retention (d) bracing and reciprocation a

b

Fig. 17.2 (a and b) Overdenture abutments can be vital or non-vital teeth. Ideally, they should be 2 mm supra-gingival. Reinforced acrylic has been used. Often a metal strengthener is needed for durability

a

b

Fig. 17.3 (a and b) Onlay provisional denture to test an increase in the occlusal vertical dimension. The onlays have to be refined in the mouth for an accurate fit. A low lip line made this appearance acceptable for this patient

236

a

K. Hemmings

b

Fig. 17.4 (a and b) Anterior overlays on a metal framework partial denture. Refinement in the mouth is usually necessary for accuracy of fit and a good appearance

(e) major connectors (f) indirect retention If teeth are reduced and retained as overdenture abutments, a number of advantages can be gained: • • • •

Decreased ridge resorption [21, 22] Psychological and emotional benefit [23] Proprioceptive feedback [24, 25] Improved masticatory efficiency and better control of mandibular movements [26] • Further retention can be gained from the addition of precision attachments such as magnets or stud attachments • Replacement of soft tissue through the use of a flange • Improved crown-root ratio of abutments. The height of the overdenture abutment should be ideally about two millimeters supra-gingivally and dome shaped [27]. The reduction in crown-root ratio will reduce the mobility of the tooth [28] There are significant disadvantages associated with overdentures: • Higher maintenance as the denture base or components can fracture if they are thin. There is a reduction in space available leading to an increased likelihood of fatigue fracture [29]. It is a wise precaution to strengthen overdenture frameworks. • Caries if plaque control is poor. A good preventive regime is vital if the overdenture abutment is going to survive in the long term [23, 30–33]. Overdenture abutments can be maintained in older patients with a history of primary dental disease by four to five recall visits per year [32]. • Periodontal breakdown is inevitable unless preventive care is good [31]. • Abutment teeth are at greater risk of periodontal breakdown without an adequate band of attached gingival tissue [34]. • Severely worn teeth do not always require root canal treatment due to the continued deposition of secondary dentine. However, there is always a risk of pulp

17  Removable Prosthodontics

237

exposure when reducing teeth and endodontic treatment may be necessary or provided electively [35, 36].

17.5.3 Complete or Partial Onlay or Overlay Dentures An overlay denture covers the damaged teeth with a full labial veneer facing and will be less bulky than an overdenture. An onlay denture will cover the occlusal or incisal part of the teeth only. They are most useful for moderately worn posterior teeth to re-establish the correct occlusal vertical dimension. The occlusal surfaces can be tooth coloured or made of a cobalt-­ chromium alloy as an integral part of the denture framework to increase their durability (Fig. 17.5a, b). The choice between an onlay, overlay or overdenture design will depend on the denture design allowing for acceptable appearance and function. The path of insertion of the denture needs to be selected on a surveyor. Gaining a favourable path of insertion for acrylic veneer facings may eliminate favourable undercuts for clasping posteriorly and needs to be considered when designing the denture (Fig. 17.6a, b). A low lip line may allow a butt joint but if this is visible an overlay component will be preferred.

17.5.4 Partial Dentures in Combination with Adhesive or Conventional Fixed Prosthodontics If teeth have not been adversely affected by wear or can be repaired to a normal contour, treatment can be simplified and conformative partial dentures provided. It may be possible to modify the teeth so that they can help to retain, support, and stabilise the denture. The following features can enhance denture design:

a

b

Fig. 17.5 (a and b) A precision retained complete overdenture requiring considerable clinical and laboratory skill. An enthusiastic patient following a strict maintenance regime will be required to prevent early failure

238

a

K. Hemmings

b

Fig. 17.6 (a) Survey lines showing undercut for clasping on the molar tooth but minimal engagement of the labial anterior undercut. An overlay facing could be provided anteriorly. (b) By tilting the cast (heels down on this maxillary cast as viewed on the surveyor) an overdenture flange could be utilised, but the molar undercut has been lost

• Preparation of rest seats, guide planes and undercut on abutment teeth • Composite additions can alter contour to favourable undercuts for clasping • Crowns if indicated could be milled to provide guide planes, rest seats, undercuts or even precision attachments There will be some concern if anterior crowns are provided and the posterior support is solely provided by partial dentures. Compliance with wearing dentures in this situation is reduced leaving the anterior crowns subject to excessive occlusal loads [37, 38].

17.6 Diagnostic or Provisional Appliances A maxillary hard heat-cured full coverage acrylic splint with or without teeth can be used in the diagnostic phase as a provisional denture (Chap. 11). It should provide even contact in the retruded contact position with anterior guidance and posterior disclusion. This appliance can be useful in testing tolerance to the planned changes in occlusal vertical dimension [39–41]. It can relax jaw muscles aiding jaw registrations but is probably most useful as an appliance to prevent further wear. Partial coverage splints should be avoided due to selective intrusion and extrusion of teeth, unless as a planned procedure using the Dahl concept [42], as the resulting malocclusion could otherwise be difficult to correct. Fully acrylic provisional appliances that have an overdenture, onlay and/or overlay design can be provided to test changes in occlusal vertical dimension, aesthetics, phonetics and function. They can also be used to test the patient’s tolerance and adaptive capacity to removable appliances. They should be designed and made with the same care as a definitive denture (Fig. 17.7a–f). They can be modified (i.e. relined or adjusted) whilst abutment teeth are being prepared to receive extra-coronal restorations or being built up with composite resin prior to making the definitive dentures.

17  Removable Prosthodontics

239

a

b

c

d

e

f

Fig. 17.7 (a) A patient with severe tooth wear presenting with non-compensated tooth wear in a depleted dentition. (b) Clinical appearance reproduced in mounted study casts. (c) Increase in occlusal vertical dimension determined in the laboratory. (d) Maxillary and mandibular wax try-in dentures made. (e and f) Provisional maxillary overdenture and mandibular partial denture in place for patient approval

17.7 Definitive Dentures Once the patient has given their approval to the provisional denture, the main features of the provisional prosthesis should be carried forward to the design of the definitive denture. The following features of the diagnostic or provisional prosthesis should be assessed: (a) (b) (c) (d) (e)

appearance lip support occlusion patient tolerance durability

240

a

K. Hemmings

b

c

Fig. 17.8 (a) Palatal view of maxillary partial denture with anterior bite plane and backings. (b) Appearance of mandibular anterior teeth at fit. (c) Worn appearance of mandibular anterior teeth after 8 years of service with wear of the mandibular anterior teeth against the metal bite plane

If major changes are planned, then a new wax try-in is indicated. If there are fractures or wear of the provisional dentures, then an increase in bulk or change of materials will be required to strengthen the definitive denture. At this stage, the soft tissues should be healthy, and the prognosis of the abutment teeth secured. If there is some doubt about this, some contingency should be built into the denture design to plan for any future failure. Concerning the occlusion, the stability of the denture and patient’s adaptation to them will be increased if guidance is maintained on the natural teeth. Therefore, an ideal occlusion is usually possible if most of their natural teeth remain and the denture is tooth borne. In the depleted dentition when the support for the dentures will be shared between the mucosa and the teeth, a bilateral balanced occlusion should be provided. Similarly, if the definitive denture opposes a complete denture a balanced occlusion is likely to better function for the patient. When the denture opposes the natural dentition, a compromise has to be sought between durability of the appliance and further wear of the natural teeth. Ideally, the occluding surfaces of the opposing teeth are made of the same material and the possibility of differential wear is avoided. If this is not possible, wear on the natural teeth should be expected and reviewed periodically. Cobalt-chrome and ceramic can be particularly damaging in this respect (Fig. 17.8a–c).

17.8 Laboratory Considerations The definitive denture design can be complex and should be agreed with technician colleagues. The design is best drawn on the laboratory card and a study cast. A visit to the technician to discuss the design is a good way to improve the design. Potential technical difficulties can be avoided at this stage which the clinician may have overlooked.

17  Removable Prosthodontics

241

17.9 Denture Base Denture bases are usually made from metal or acrylic. Acrylic can be aesthetic and easily adjusted and relined. Resin bases need to be at least 2–3 mm thick but to gain strength they can become bulky. They are likely to abrade and curing stresses can lead to distortions [43]. They can be more prone to plaque accumulations. Overdenture abutments can compromise the space for the denture base and prosthetic teeth. If acrylic is used as the base, then a metal strengthener may be required. Metal-based dentures that can be cast in either gold, cobalt-chrome or titanium alloys are more difficult to reline and adjust. However, metals do have many of the desirable properties of a denture base as shown in the list below [44]: • • • • •

Accurate fit Inert material with a good finish Lightweight in the mouth Sufficient strength Easy to clean

17.10 Prosthetic Teeth The prosthetic teeth will have the best appearance if they are tooth coloured. This may not be as important when replacing posterior teeth as space may be at a premium. In thin section metal will perform the best and may be acceptable to patients if durability is their prime concern. Various materials for prosthetic teeth are available: • Acrylic resin—they need to be provided in sufficient bulk without thin or sharp edges. Most often, stock denture teeth are trimmed to thin section and then chemically bonded to the acrylic resin base or attached to a metal base through mechanical retention and chemical bonding. An adhesive containing 4-­methacryloxyethyl trimellitate anhydride (4-meta) can be used to bond acrylic resin to metal-based dentures. The low abrasion resistance can make acrylic a kind material to the opposing teeth, easy to adjust but prone to wear or fracture in patients who parafunction. Sometimes the best appearance is achieved by carrying out a chairside reline of labial facings (Fig. 17.4b). • Porcelain—these can provide excellent aesthetics but are brittle and very abrasive once they lose their surface glaze. They can also make a clicking sound in function. They can be bonded to metal-based dentures through a process of tribochemical coating. • Composite—whilst composite combines the best physical features of acrylic and porcelain, it is relatively brittle in thin section. To provide good performance, it would have to be provided in a thickness of at least 2–3 mm and be protected by the denture base.

242

a

K. Hemmings

b

Fig. 17.9 (a) Macro-mechanical and micro-mechanical retention needs to be applied to the partial denture design. In this case with beads and struts to retain anterior overlay veneers. (b) Further protection of acrylic components with palatal backings in this case extended up to the incisal edge

• Cobalt-chrome alloy—such alloys can be cast in thin section and still provide good strength and rigidity. The occlusal surfaces and palatal backings can be cast as part of the overall framework. The metal is difficult to adjust and is abrasive to the opposing dentition. It can be particularly useful for covering worn posterior teeth as onlays where space is limited. • Gold alloy—gold will cause the least abrasion to natural teeth and is more easily adjusted. Cast gold onlays or backings can be attached to acrylic teeth. This is an expensive option. Once dentures have been fitted and adjusted a remount procedure involving pick-up impressions of the dentures, facebow recording and inter-­ cuspal jaw registration will allow attachment in the laboratory. Tooth coloured veneering materials can be the weak link in the durability of partial and complete dentures made for patients with tooth wear [45]. Macromechanical and micromechanical retention needs to be applied to the denture design. Retentive beads, ‘nail heads’ and struts can be combined with palatal metal backings to protect acrylic, composite or porcelain components. On occasion, these backings or onlays need to be extended up to the incisal edge or occlusal contacting surfaces to provide sufficient protection (Fig. 17.9a, b).

17.11 Conclusion, Prevention and Maintenance Patients with tooth wear who have been provided with dentures are generally older and are prone to primary disease. They often find plaque control difficult as sight and manual dexterity is compromised even if they are motivated. The use of dentures will compound these difficulties as the dentures enhance plaque accumulation [12]. Prevention should be encouraged as far as is practicable and these patients should be managed similarly to patients with a high caries risk [45]. Preventive dental care should be stressed with particular attention directed to brushing the remaining abutment teeth with a high fluoride concentration

17  Removable Prosthodontics

a

243

b

Fig. 17.10 (a) Failure of an acrylic complete overdenture. (b) Failure in a partial metal framework denture. A more robust design could avoid early failure in the future

toothpaste. Dentures should be cleaned after meals, left out at night and soaked in a denture cleansing solution as directed. High concentration fluoride gels applied to the fit surface of the denture and fluoride mouthwashes used at a different time will also help [46, 47]. An occlusal splint with or without replacement teeth can be made for the patient to be worn at night to protect the abutment teeth from parafunction. If the denture design has not been sufficiently robust, early failures should be expected (Fig. 17.10a, b). Frequent failure of denture components in tooth wear patients will be attributable to: (a) occlusal factors (b) design factors (c) incorrect choice of material In this group of patients who have experienced severe tooth wear, there will be a need for frequent maintenance and a proportion of early failures should be expected. Patients should be informed of the risks at the outset together with the need for regular recall.

References 1. Faigenblum M. Removable prostheses. Br Dent J. 1999;186(6):273–6. 2. Packer ME, Davis DM. The long-term management of patients with tooth surface loss treated using removable appliances. Dental Update. 2000;27:454–8. 3. Tallgren A. Changes in adult face height due to ageing, wear and loss of teeth and prosthetic treatment. Acta Odont Scand. 1957;15(Suppl. 24):73. 4. Thompson JL, Kendrick GS. Changes in the vertical dimension of the human skull during the third and fourth decades of life. Anat Rec. 1964;27:209. 5. Murphy T. Compensatory mechanisms in facial height adjustment to functional tooth attrition. Aust Dent J. 1959;4:312–23. 6. Berry DC, Poole DFG.  Attrition: possible mechanisms of compensation. J Oral Rehab. 1976;3:201–6. 7. Sicher H. Oral biology. St Louis: CV Mosby Co.; 1949. (in Tallgren 1957)

244

K. Hemmings

8. Dawson P.  Evaluation, diagnosis and treatment of occlusal problems. 2nd ed. Toronto: Mosby; 1989. 9. Watson IB, Tulloch EN.  Clinical assessment of cases of tooth surface loss. Br Dent J. 1985;159:144–8. 10. Russell MD.  The distinction between physiological and pathological attrition: a review. Ir Dent Assoc. 1987;33:23. 11. Stern N, Brayer L.  Collapse of the occlusion—aetiology and treatment. J Oral Rehabil. 1975;2:1–19. 12. Addy M, Bates JF. Plaque accumulation following the wearing of different types of removable partial dentures. J Oral Rehabil. 1979;6(2):111–7. 13. Kayser AF. Shortened dental arches and oral function. J Oral Rehabil. 1981;8:457–62. 14. Kanno T, Carlsson GE. A review of the shortened dental arch concept focusing on the work by the Kayser/Nijmegen group. J Oral Rehabil. 2006;33:850–62. 15. Milosevic A, Burnside G.  The survival of direct composite restorations in the management of severe tooth wear including attrition and erosion: a prospective 8-year study. J Dent. 2016;44:13–9. 16. Jepson NJA, Thomason JM, Steele JG. The influence of denture design on patient acceptance of partial dentures. Br Dent J. 1995;178:296–300. 17. Steele JG, Treasure ET, O’Sullivan I. Adult Dental Survey 2009: transformations in British oral health 1968–2009. Br Dent J. 2012;213:523–7. 18. Feine JS, Carlsson GE, Awad MA, Chehade A, Duncan WJ, Gizani S, Head T, Heydecke G, Lund JP, MacEntee M, Mericske-Stern R, Mojon P, Morais JA, Naert I, Payne AG, Penrod J, Stoker GT, Tawse-Smith A, Taylor TD, Thomason JM, Thomson WM, Wismeijer D. The McGill consensus statement on overdentures. Mandibular two-implant overdentures as first choice standard of care for edentulous patients. J Prosthet Dent. 2002;88:123–4. 19. Thomason JM, Heydecke G, Feine JS, Ellis JS. How do patients perceive the benefit of reconstructive dentistry with regard to oral health related quality of life and patient satisfaction? Clin Oral Implants Res. 2007;18:168–88. 20. Hemmings KW, Howlett JA, Woodley NJ, Griffiths BM.  Partial dentures for patients with advanced tooth wear. Dent Update. 1995;22(2):52–9. 21. Crum RJ, Rooney GE Jr. Alveolar bone loss in overdentures: a 5-year study. J Prosthet Dent. 1978;40:610–3. 22. Van Waas MA, Jonkman RE, Kalk W, Van‘t Hof MA, Plooij J, Van OSJH. Differences two years after tooth extraction in mandibular bone reduction in patients treated with immediate overdentures or with immediate complete dentures. J Dent Res. 1993;72:1001–4. 23. Toolson BL, Smith DE. A five-year longitudinal study of patients treated with overdentures. J Prosthet Dent. 1983;49:749–56. 24. Basker RM, Harrison A, Ralph JP, Watson CJ. Overdentures in general dental practice. 3rd ed. London: British Dental Association; 1993. 25. Kay WD, Abes MS.  Sensory perception in overdenture patients. J Prosthet Dent. 1976;35: 615–9. 26. Rissin L, House JE, Manly RS, Kapur KK. Clinical comparison of masticatory performance and electromyographic activity of patients with composite dentures. Overdentures and natural teeth. J Prosthet Dent. 1978;39:508–11. 27. Morrow RM, Feldman EE, Rudd KD, Torvillion HM. Tooth-supported complete dentures: an approach to preventive prosthodontics. J Prosthet Dent. 1969;21:513–22. 28. Dolder EJ. The bar joint mandibular denture. J Prosthet Dent. 1961;11:689–707. 29. Langer Y, Langer A. Root-retained overdentures: Part I—Biomechanical and clinical aspects. J Prosthet Dent. 1991;66:784–9. 30. Toolson LB, Smith DE. A 2-year longitudinal study of overdenture patients. Part 1. Incidence and control of caries on overdenture abutments. J Prosthet Dent. 1978;40:486–91. 31. Toolson LB, Taylor TD. A 10-year report of a longitudinal recall of overdenture patients. J Prosthet Dent. 1989;62:179–81.

17  Removable Prosthodontics

245

32. Budtz-Jørgensen E.  Prognosis of overdenture abutments in elderly patients with controlled oral hygiene. A 5-year study. J Oral Rehabill. 1995;22:3–8. 33. Ettinger RL, Taylor TD, Scandrett FR. Treatment needs of overdenture patients in a longitudinal study: five-year results. J Prosthet Dent. 1984;52:532–6. 34. Zamikoff II. Overdentures-theory and technique. J Am Dent Assoc. 1983;86:853–7. 35. Harran Ponce E, Canalda Sahli C, Vilar Fernandez J A. Study of dentinal tubule architecture of permanent upper premolars: evaluation by SEM Aust Endo J 2001; 27: 66-72. 36. Zaslansky P, Zabler S, Fratzl P. 3D Variations in human crown dentin tubule orientation: a phase-contrast microtomography study. Dent Mater. 2010;26:e1–10. 37. Anderson JN, Bates JF.  Cobalt chromium partial denture. A clinical survey. Br Dent J. 1959;107:57–62. 38. Witter DJ, Van Elteren P, Kayser AF. Oral comfort in shortened dental arches. J Oral Rehabil. 1990;17(1):37–143. 39. Ramfjord S, Ash MM.  Biteplates, biteplanes and occlusal splints. ln: Occlusion', 3rd ed. Philadelphia: WB Saunders Co. 1983; pp.359-375. 40. Ramfjord SP, Ash MM. Reflections on the Michigan splint. J Oral Rehabil. 1994;21(5):491–500. 41. Howat A P, Capp N J, Barrett N V J. Occlusal splint therapy. ln: A colour Atlas of occlusion and malocclusion. London: Wolfe, 1991; pp.69-72. 42. Poyser N, Porter R, Briggs P, et  al. The Dahl concept: past, present and future. Br Dent J. 2005;198:669–76. 43. Carr AB, Brown DT.  McCracken’s removable partial prosthodontics. 12th ed. Elsevier Mosby; 2011. 44. Woodley NJ, Griffiths BM, Hemmings KW. Retrospective audit of patients with advanced tooth wear restored with removable partial dentures. Eur J Prosthodont Restor Dent. 1996;4:185–91. 45. Public Health England. Delivering better oral health: an evidence-based toolkit for prevention. https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/605266/ Delivering_better_oral_health.pdf. [Accessed March 2017] (Online publication). 46. Hussey DL, Linden GJ.  The efficacy of overdentures in clinical practice. Br Dent J. 1986;161:104–7. 47. Narhi TO, Ettinger RL, Heilman JR, Wefel JS. Salivary fluoride levels in overdentures wearers after topical fluoride gel application. Int J Prosthodont. 1997;10:553–61.

Dental Implants in the Management of Tooth Wear

18

Pranay Sharma and Pratik Sharma

18.1 Introduction The literature confirms implant therapy as being a safe and predictable treatment modality in carefully selected patients with one systematic review reporting survival rates of nearly 95% at 13-year follow-up [1]. However, failures and complications can occur when using implants. Most of these failures are preventable with appropriate patient selection and meticulous treatment planning and execution. Patients who present with tooth wear requiring dental implants pose specific dental problems requiring careful evaluation prior to considering implant therapy. Indications for providing tooth wear patients with dental implants include restoring function, aesthetics and occlusal stability. Prior to focusing on the specifics of managing tooth wear patients with dental implants, it is important to share latest approaches to replacing a single tooth with an implant-supported tooth (Figs.  18.1–18.5) and to also review current thinking regarding implant features and patient factors. Implant design is aimed at achieving primary mechanical stability and stimulating a durable bone-implant interface over time through osseointegration. Both macro- and micro-mechanical features of the implant design assist in this process.

P. Sharma (*) UCL Eastman Dental Institute, London, UK e-mail: [email protected] P. Sharma Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, UK e-mail: [email protected] © Springer Nature Switzerland AG 2022 A. Eder, M. Faigenblum (eds.), Tooth Wear, BDJ Clinician’s Guides, https://doi.org/10.1007/978-3-030-86110-0_18

247

248 Fig. 18.1 Surgical placement of a dental implant showing favourable bone volume to stabilise the implant

Fig. 18.2 Osseo-­ integrated implant at review with good soft tissue profile and keratinised tissue

Fig. 18.3 Screw-retained porcelain fused to metal implant crown

P. Sharma and P. Sharma

18  Dental Implants in the Management of Tooth Wear Fig. 18.4  Single tooth implant restoration showing good aesthetic and functional integration

Fig. 18.5 Peri-apical radiograph showing appropriate implant positioning, peri-implant bone levels and restoration fit

249

250

P. Sharma and P. Sharma

18.1.1 Macro-Mechanical Features The majority of implants used in clinical practice today are threaded and of a cylindrical or conical shape. The length, diameter and thread design are also parameters that affect stability within the bone. The incorporation of threads improves initial stability, enlarges implant surface for osseointegration and distributes stress favorably. Incorporation of micro-threads at the neck of the implant enhances bone contact and promotes more favorable stress distribution aiding reduction in crestal bone loss.

18.1.2 Micro-Mechanical Features Typically, dental implants are made from grade 4 commercially pure titanium, titanium alloys, and, more recently, ceramic materials such as zirconia oxide. Most commercially available implants now have a micro-roughened surface as this enhances osseointegration through increased surface area for bone to implant contact and accelerates peri-implant bone healing. Various techniques increase surface roughness; these include machining, plasma spraying, grit-blasting, acid-etching, anodization, laser treatment and coating [2]. Chemical alteration of the micro-­roughened surface with some form of bio-active coating (e.g. calcium phosphates, bone morphogenetic proteins and fluoride ions) can further enhance osseointegration [3].

18.1.3 The Implant-Abutment Connection Many contemporary implant systems now have an internal connection (restorative components fit within the implant) rather than an external connection (restorative components fit on top of the implant). The advantages of an Internal connection are described in Table 18.1.

18.1.4 Patient Selection When considering implant therapy, the clinician must evaluate at the outset whether implants are appropriate for that individual taking into account their specific oral condition and also the role that the implants will play as part of an overall comprehensive care plan. A thorough patient assessment is a pre-requisite to adequate treatment planning and this should take into account the patient’s presenting complaints, dental history, social history and medical history. Table 18.1  Advantages of internal connection  • Mechanical: anti-rotation feature, improved fit/reduced micro-gap and reduced micro-movement  •  Biological: improved seal against microbial contamination  • Clinical: Ability to ‘platform switch’ resulting in improved marginal bone stability, stabilisation of soft tissue and improved aesthetics

18  Dental Implants in the Management of Tooth Wear

251

Table 18.2  Contra-indications and increased risk for implant therapy Absolute medical contra-indications:  •  Active cancer treatment: chemotherapy  •  Acute infectious diseases  •  Uncontrolled psychosis  •  Uncontrolled drug or alcohol abuse  •  Recent myocardial infarction, cerebrovascular accident, valvular prosthesis surgery  •  Intravenous bisphosphonate medication  •  Pregnancy  •  Immuno-suppression: systemic disease, organ transplantation Intra-oral contra-indications and increased risk:  •  Intra-oral hard and/or soft tissue pathology  •  Poor quantity/quality of bone and soft tissue  •  History of periodontitis  •  Inability to maintain plaque control: physical/mental impairment  •  Parafunction and bruxism  •  Smoking  •  Post-head and neck radiation therapy: especially within last 1 year  •  Uncontrollable diabetes  •  Osteoporosis

Very few absolute medical contra-indications for the provision of treatment with dental implants exist and these, along with other relative contra-indications, are shown in Table 18.2.

18.1.5 Patient Age The chronological age of a patient per se is not a contraindication for implant placement. In young adults, implant treatment should be delayed until cessation of cranio-­ facial growth which is usually around the age of eighteen. However, facial skeletal growth can continue into the third decade of life and so it may be prudent, where possible, to postpone implant placement until after the age of 25, especially in the anterior region [4]. In elderly patients, one needs to consider treatment necessity and the patient’s ability to tolerate the procedure alongside any medical contra-indications.

18.1.6 Smoking Some studies have reported that insertion of implants in smokers affected failure rates, risk of post-operative infections, peri-implantitis and marginal bone loss [5] whilst others reported more favorable survival rate outcomes. Smoking should be viewed as a relative contra-indication for implant treatment and smoking status should be assessed and patients who smoke should be informed of potentially lower success and survival rates.

252

P. Sharma and P. Sharma

18.1.7 History of Periodontal Disease Patients with a history of periodontitis are at higher risk of developing peri-­ implantitis [4]. Poor oral hygiene has also been implicated in the development of peri-implantitis. Periodontal disease stabilisation, together with patient commitment, must be achieved prior to embarking on implant treatment with appropriate periodontal maintenance both during and following treatment.

18.2 B  ruxism and the Effects of Parafunction on Implant-Supported Restorations Previous chapters have discussed the role of parafunction and bruxism in the aetiology of tooth wear. Clinical research assessing the impact of bruxism on dental implants, however, is limited as many studies exclude participants with bruxism. Whilst the available literature suggests a causal relationship between bruxism and fracture of the supra-structure, no direct relationship between bruxism and dental implant failure has been shown [6]. Furthermore, some researchers have also suggested that bruxism never influences the marginal bone loss seen around dental implants [7]. Despite this, many clinicians still believe that occlusal overload through parafunction or bruxism is a risk factor for peri-implant bone loss and plan accordingly to limit the risk (Table 18.3). It is likely that forces applied to implants during bruxism are even higher than those exerted onto natural teeth due to the decreased proprioception of implants. The consequences of overload of dental implants can present as late biological and/or biomechanical complications [8]. Late biological complications will normally present as pathological bone loss despite complete integration having been achieved previously. Biomechanical complications resulting from overload may manifest as implant component failure; for example, fracture of the implant itself, loosening or fracture of abutment screws, loosening or excessive wear of attachment systems in overdentures, and excessive wear or fracture of supra-structural porcelain, composite or acrylic teeth [9].

18.3 P  rosthodontic Design and the Choice of Restorative Materials Fastidious clinical assessment and planning is required in these patients to negate the risk of potential complications, this should include a carefully devised occlusal Table 18.3  Treatment planning considerations for implant reconstruction in patients with bruxism  • Increasing implant-bone surface area: consider longer implants where possible and wider implants in molar regions. Additional implants if feasible  •  Optimising crown to implant ratio  •  Eliminating or minimising the extent of cantilevers  •  Splinting of implants to distribute occlusal forces  •  Metal occlusal surfaces where possible to reduce risk of porcelain fracture

18  Dental Implants in the Management of Tooth Wear

253

scheme and adequate mechanical design of the restoration. Assessment of the occlusal vertical dimension is required to confirm adequate space for an optimally designed prosthesis. In situations with a reduced occlusal vertical dimension, a resulting lack of inter-occlusal space may lead to inadequate dimensions of the framework and/or restorative material, resulting in an increased risk of technical complications. The need to re-establish or increase the occlusal vertical dimension in such cases should be considered. The occlusal principles described for fixed prosthodontics on natural teeth are equally acceptable for restoration on dental implants. Occlusal considerations for implant prostheses should be aimed at minimising cuspal interferences, concentrating forces along the long axis, and reducing lateral forces [8]. Unlike natural teeth, dental implants lack the protective proprioceptive feedback imparted by the periodontal ligament so long-term monitoring of the occlusion and some form of protection following completion of treatment, such as an occlusal splint for night wear is also recommended (Chaps. 11 and 19). In an effort to protect the bone-implant interface, the use of shock-absorbing materials such as acrylic resin on top of the supra-structure was advocated for many years. However acrylic resin is prone to wear of the occlusal surface and fracture over time [10], as shown in the clinical case in Fig. 18.6. For single tooth and fixed partial implant restorations, ceramic has become the material of choice for the occlusal surface, due to its superior wear resistance and aesthetics. A range of restorative materials are available for full-arch fixed prostheses on implants, including metal ceramic prostheses and more recently zirconia-based restorations, however many clinicians continue to use acrylic resin teeth as the material of choice. Some clinicians prefer metal restorations on occlusal surfaces rather than porcelain to protect the implant prostheses in patients with bruxism, especially for posterior teeth [8]. An example of a reconstruction with metal occlusal surfaces is shown in Fig.  18.7. The current evidence for the ideal occlusal restorative material in implant prostheses for patients with bruxism is sparse and further clinical research is needed to provide more definitive recommendations and guidelines. Fig. 18.6 Maxillary hybrid prosthesis showing wear of the acrylic teeth on the occlusal surfaces

254

P. Sharma and P. Sharma

Fig. 18.7  Maxillary arch restored in a patient with bruxism: an extensive implant supported bridge with gold crowns on the first molar teeth, all with metal occlusal surfaces

Table 18.4  Implant treatment planning work-flow  • Articulated study casts in the appropriate jaw relation or digitally scanned and virtually mounted jaws/models for further planning  • Decide whether case warrants a conformative or re-organised approach. Is there a need for space creation? If so, how will this be achieved (e.g. orthodontics or increasing the vertical dimension of occlusion)?  • Diagnostic tooth wax-up/set-up or digital virtual wax-up used to aid construction of a radiopaque radiographic guide  • Radiographic imaging with cone beam CT scan if deemed clinically justified, with template in-situ for scan  • 3D analysis of available bone volume for optimal implant placement and positioning in relation to the desired final tooth positions. Use of 3D planning software can facilitate this process  • If insufficient bone volume, then consider whether suitable bone regenerative procedures are required to allow the correct positioning of the implants according to the restorative requirements or consider modifying surgical/restorative plan  • Manufacture of a surgical guide based on the 3D planning for static guided implant placement or utilise planning to dynamically navigate implant placement

18.4 Restoratively Guided Treatment Protocol All implant planning and surgical placement requires a prosthetically driven approach. The optimal position of the teeth and definitive restoration should be planned first and this information then fed back to facilitate ideal implant placement within the bone. Previous chapters have covered aspects of treatment planning, data collection, special tests and diagnostic procedures. A sample work-flow for dental implant planning is outlined in Table 18.4. Figures 18.8–18.13: Highlight some of the implant treatment planning work-­ flow using analogue (Figs.  18.8 and 18.9) and digital techniques (Figs. 18.10–18.13).

18  Dental Implants in the Management of Tooth Wear

255

Fig. 18.8 Analogue technique: articulated study casts and diagnostic wax-up for implant planning

Fig. 18.9 Analogue technique: tooth supported acrylic radiographic/ surgical guide, to aid implant placement

The presence of adequate space for both implant and restoration, healthy adjacent teeth, favourable neighbouring root alignment, sufficient bone quantity and adequate soft tissue volume are good predictors for successful implant treatment to replace single or multiple teeth. Such a fixed solution is particularly valuable in the distal extension saddle situation to provide posterior support when providing care for patients with tooth wear elsewhere (Fig. 18.14).

18.4.1 Timing of Implant Placement Immediate implant placement into fresh extraction sockets provides some advantages such as reducing the number of surgical appointments and overall treatment

256 Fig. 18.10 Digital technique: use of cone beam CT scan to plan implant placement

Fig. 18.11 Digital technique: 3D planning software to optimise implant placement in relation to final restoration. From this, a surgical guide can be made

P. Sharma and P. Sharma

18  Dental Implants in the Management of Tooth Wear

257

Fig. 18.12 Digital technique: impression of implants with intra-oral scanner (Trios 3-shape)

Fig. 18.13 Digital technique: design of implant restorations using CAD software

time. Immediate implants should only be considered in carefully selected patients and sites with no active pathology, adequate bone volume to provide implant stability and favourable soft tissues to optimise aesthetics [11]. Figures  18.15–18.17 shows an example of an immediate placement implant clinical case in the anterior

258 Fig. 18.14 Implant placement in mandibular Kennedy 1 situation to be restored with fixed bridgework to provide posterior support in a patient with anterior tooth wear

Fig. 18.15 Atraumatic extraction of fractured upper right central incisor root

Fig. 18.16 Immediate implant placement and socket grafted buccally with particulate xenograft material

P. Sharma and P. Sharma

18  Dental Implants in the Management of Tooth Wear

259

Fig. 18.17 Definitive implant supported crown displaying good soft tissue profile and aesthetic integration

Fig. 18.18  Upper right central incisor site 6 weeks after extraction showing soft tissue closure and favourable contour

Fig. 18.19 Prosthetically driven implant placement using surgical guide

aesthetic zone. The clinical case highlighted in Figs.  18.18–18.23 shows early implant placement protocol delayed until 6 weeks after tooth extraction.

18.5 Replacing Missing Teeth in Patients with Tooth Wear Patients presenting with tooth-wear may require implant-supported restorations to restore function, aesthetics and provide occlusal stability, as part of an overall

260

P. Sharma and P. Sharma

Fig. 18.20 Note significant buccal bone loss and several exposed implant threads following tooth extraction

treatment plan. This may involve replacement of a single tooth or multiple missing teeth or restoration of an entire jaw. In some cases, where the extent of tooth wear is so advanced and affecting many teeth a decision needs to be made whether to remove some or all of the remaining teeth. Treatment options for replacement of missing teeth with dental implants are summarised in Fig. 18.24 [12].

18.5.1 Partially Dentate Patients 18.5.1.1 Single Implant-Supported Tooth Single tooth implant restorations are either screwed directly to the implant (screw-­ retained) or cemented to a trans-mucosal abutment (cement-retained). For a cement-­ retained restoration, the abutment is attached to the implant through a screw-joint and the restoration is cemented to the abutment in the same way as conventional crowns. An example of a cement retained restoration is shown in Figs. 18.25 and 18.26. The abutment component is used to connect the crown to the implant. In screw-retained implant restorations, the restoration and the abutment are a single

18  Dental Implants in the Management of Tooth Wear Fig. 18.21  Guided bone regeneration technique used to manage the buccal defect using xenograft particulate graft mixed with autogenous bone chips

Fig. 18.22 Collagen membrane placed over particulate graft

261

262

P. Sharma and P. Sharma

Fig. 18.23  Tension free soft tissue closure

Missing tooth

Single implant supported crown

Missing multiple adjacent teeth

Missing multiple nonadjacent teeth

Fixed implant supported bridge

Removable implant supported bridge

Fully Edentulous jaw

Fixed implant supported prosthesis

Screw-retained

Cement-retained

Hybrid

Removable implant supported overdenture

Porcelain fused to metal Zirconia

Fig. 18.24  Treatment options for replacement of missing teeth with dental implants [12]

18  Dental Implants in the Management of Tooth Wear

263

Fig. 18.25 Abutment in-situ

Fig. 18.26 Cement retained zirconia crown supported on a ceramic abutment

Table 18.5  Abutment types  •   •   •   • 

Custom made: e.g. UCLA fabricated using lost-wax technique Pre-fabricated: modifiable or non-modifiable All-ceramic abutments: aesthetic advantages in thin gingival biotypes CAD-CAM milled

unit which is attached to the implant directly via a prosthetic screw (Figs.  18.3– 18.5) [13, 14]. Table 18.5 outlines the range of abutment types available.

18.5.1.2 Fixed Implant-Supported Bridge In principle, this type of restoration resembles conventional bridgework in that it provides a fixed prosthesis to replace multiple missing teeth, as shown in Figs. 18.27 and 18.28. The prosthesis could be screw or cement retained as described above for single tooth restorations. The number of implants used to support this type of prosthesis will depend largely on the extent of the edentulous span and could typically involve the use of between two and six implants.

264

P. Sharma and P. Sharma

Fig. 18.27  Three unit screw retained porcelain fused to metal bridge

Fig. 18.28 Porcelain fused to metal bridge to restore the maxillary left free end saddle and provide posterior support

18.5.1.3 Removable Implant-Supported Prosthesis Occasionally, due to clinical factors, multiple missing teeth cannot always be restored with a fixed implant supported restoration, for example where there is insufficient bone volume to place enough implants for a fixed bridge. Other factors may include extensive ridge resorption resulting in the need for a flange to restore lip and facial support. In such cases, a removable partial denture combined with the remaining available teeth can be a viable treatment option. One or more implants with a suitable attachment system may also be helpful to enhance support and retention over the edentulous ridge.

18  Dental Implants in the Management of Tooth Wear

265

18.5.2 Fully Edentulous Patients 18.5.2.1 Removable Implant-Supported Overdenture This type of prosthesis can be removed by the patient and gains support and retention from the implants in conjunction with a suitable attachment system. The attachment is a mechanical device used for retention and stabilisation of the removable prosthesis. The attachment consists of two parts, one part is attached to the implant (patrix/male component), while the other part is attached to the prosthesis (matrix/ female component). Table 18.6 displays the main attachment systems for implant overdentures. Implant overdentures can be classified as primarily tissue supported or entirely implant supported. The distinction between the two is important as it dictates the overall design of the prosthesis and the type of attachment system used. Tissue supported prostheses obtain support from the residual ridges and should, therefore, extend to cover the supporting tissues in a similar fashion to a conventional complete denture, as shown in the clinical case of a mandibular overdenture in Figs. 18.29–18.31. Typically, two implants are utilised in the anterior mandible and four implants are placed in the anterior maxilla for a maxillary overdenture [15]. An example of a maxillary overdenture is shown in Figs. 18.32–18.34. Fully implant supported overdentures typically utilise four implants in the mandible and up to six implants in the maxilla. They are fully implant supported and retained and as such have less tissue coverage and flange [16]. Table 18.6  Attachment systems for implant overdentures Non-splinted (implants not linked together)  •  Locator attachment  •  Stud/ball attachment  •  Magnets Splinted (implants linked together)  •  Bar/clip attachments  •  Milled framework

Fig. 18.29 Anterior mandible showing locator attachments on two implants

266

P. Sharma and P. Sharma

Fig. 18.30 Mandibular implant overdenture showing optimal posterior extension for tissue support and locator housings anteriorly within the confines of the denture

Fig. 18.31 Mandibular implant overdenture supported on two implants with locator attachments

Fig. 18.32  Maxillary arch with four implants and bar attachment

18.5.2.2 Fixed Implant-Supported Prosthesis In contrast to the removable approach outlined above, such prostheses cannot be removed by the patient and are usually supported by four or more implants. The volume and tissue coverage of the prosthesis is reduced in comparison to a removable overdenture. There are two basic types: a screw-retained hybrid prosthesis or a more conventional form of fixed bridge [16, 17]. The clinical case shown in Figs.  18.35–18.38 shows an edentulous maxillary arch restored with a screw-­ retained hybrid prosthesis.

18  Dental Implants in the Management of Tooth Wear Fig. 18.33 Maxillary implant overdenture with metal support and clip attachments

Fig. 18.34 Maxillary implant overdenture supported on four implants with bar and clip attachments

Fig. 18.35  Maxillary arch with multi-unit abutments in-situ on five implants

267

268

P. Sharma and P. Sharma

Fig. 18.36 Maxillary screw-retained hybrid prosthesis with acrylic teeth and flange

Fig. 18.37 Occlcusal view of maxillary screw-retained hybrid prosthesis

Fig. 18.38  Anterior view of maxillary screw-retained hybrid prosthesis

The hybrid prosthesis is screw-retained and constructed of a metal substructure, usually a titanium milled bar and acrylic denture teeth incorporating a partial acrylic flange. Figures 18.39–18.41 shows a severe tooth wear case where the mandibular

18  Dental Implants in the Management of Tooth Wear

269

Fig. 18.39  Severe tooth wear requiring extensive reconstruction using a re-organised approach

Fig. 18.40 Mandibular arch showing placement of four implants to support a screw-retained hybrid prosthesis

Fig. 18.41 Mandibular arch restored with screw-retained implant hybrid bridge

arch has also been restored with a screw-retained hybrid prosthesis supported by four mandibular implants. Fixed implant supported bridges can be either screw or cement retained. They comprise of a metal substructure and porcelain in a similar fashion to conventional porcelain-fused-to-metal restorations. Ceramic materials like zirconia are becoming increasingly popular for fabricating such fixed bridges.

270

P. Sharma and P. Sharma

18.6 T  he Role of Implants to Facilitate Orthodontics in Partially Dentate Patients The development of dental implants has revolutionised the field of orthodontics as a source of providing absolute anchorage. Anchorage management is an essential component of successful orthodontic treatment and osseo-integrated implants with their inherent property of being able to resist movement under forces of loading lead them to be widely used for this purpose. In 1989, Roberts et al. describe the use of such implants to successfully provide anchorage to close large extraction space in the first permanent molar region of the mandible [18]. More recently, the advent of orthodontic mini-implants (OMIs) and the significant research conducted within this area over the last 20 years has further advanced the applications to the extent where orthodontists are using OMIs routinely for anchorage control. Despite an array of commercially available designs, typical most OMI body dimensions are in the region of 1.2−2 mm in diameter and 6−10 mm in length. In contrast to conventional dental implants, they rely on mechanical retention within bone. Owing to their relatively minimalistic size and method of retention, they are easy to insert and remove and can be placed in a variety of intra-oral sites in the mandible and maxilla to facilitate tooth movement (Figs.  18.42, 18.43, and 18.46). Fig. 18.42 Over-eruption of maxillary posterior teeth with lack of inter-occlusal space for an implant retained prosthesis in the mandibular arch. Intrusion of molars in the buccal segments is anchorage demanding and can be facilitated with the use of OMIs

Fig. 18.43  Intrusion of maxillary molar teeth with OMI to provide inter-­ occlusal space for implant retained prosthesis in the mandibular arch

18  Dental Implants in the Management of Tooth Wear

271

Fig. 18.44 Successful intrusion of maxillary molar teeth with OMI creating space for prosthodontic rehabilitation

Fig. 18.45  Tooth wear and significant asymmetric over-eruption of the dentition. Successful management of tooth wear will require levelling of the maxillary teeth and reduction of the overbite

Fig. 18.46 Asymmetric intrusion of dentition with use of OMI for anchorage support prior to restorative treatment

Interdisciplinary cases, including those with tooth wear often require complex tooth movements to allow for restorative / prosthetic rehabilitation. Implants can provide a critical source of anchorage to facilitate the following tooth movements to help manage such cases; retracting, protracting and aligning teeth with limited anterior or posterior support (Fig.  18.42), intruding or extruding anterior / posterior teeth (Figs. 18.43, 18.44 and 18.46), selective asymmetric movement of a group of teeth (Figs. 18.45–18.47) and provide anchorage for teeth with limited periodontal support.

272

P. Sharma and P. Sharma

Fig. 18.47 Successful levelling of the upper arch and reduction in overbite achieved with OMI for anchorage support. Patient now ready for restorative management

18.7 Long Term Maintenance and the Use of Occlusal Splints Despite high success rates, implant complications and failures do occur. Factors related to appropriate patient selection and treatment planning have been addressed previously. An implant may fail to integrate with the peri-implant tissue during the healing stage. This type of failure is described as an early failure, prior to the implant being loaded in function. The implant may also lose its integration and fail at a later stage, months or even years after implant placement. This is termed a late failure. Such late failures can be attributed to either biological or mechanical problems [19].

18.7.1 Biological Failures Such failures can occur because of peri-implant tissue inflammation in response to bacteria that forms a biofilm on the implant surface [20]. This tissue response may be limited to the peri-implant soft tissues only (peri-implant mucositis) or may also extend to and affect the peri-implant bone and lead to its resorption (peri-­implantitis). Clinically, peri-implant mucositis may present with redness, bleeding on probing and increased pocket depths with no crestal bone loss. Peri-implantitis critically will also manifest with crestal bone loss of a circumferential pattern around the implant, as shown in Figs. 18.48–18.50. The prevalence of peri-implant disease has been reported in the literature to range from 2% to 62%. In a recent systematic review, the weighted mean prevalence of peri-implantitis was reported as 22% [21] and is likely to increase as more implants are placed worldwide. Clinicians need to monitor implant restorations both clinically and radiographically at suitable intervals to assess peri-implant tissues and if disease is noted then intervention can be commenced at an early stage. The patient also has a significant role to play in maintaining good oral hygiene and adhering to personalised maintenance programmes. Various surgical and non-surgical treatment modalities have been proposed for the treatment of peri-implantitis although at present there is no clear consensus. Approaches advocated include mechanical debridement, use of antiseptics and local or systemic antibiotics, as well as surgical access and regenerative procedures.

18  Dental Implants in the Management of Tooth Wear

273

Fig. 18.48 Peri-apical radiograph of implant in site of lower right first molar showing circumferential crater shaped pattern of bone loss

Fig. 18.49 Peri-­ implantitis affecting maxillary implants with suppuration and soft tissue swelling

18.7.2 Mechanical Failures These may occur because of inadequate treatment planning, unsatisfactory prosthetic design and an unfavourable occlusal scheme resulting in potentially damaging occlusal loading. These have been described earlier in the chapter. One systematic review found increased mechanical risks for implant retained fixed partial dentures in bruxers compared to non-bruxers [22]. Figure 18.51 shows fracture of the acrylic teeth on a mandibular hybrid bridge. Removable implant supported overdentures require more long-term maintenance due to mechanical complications in comparison to fixed restorations. In the presence of recurrent mechanical complications, careful assessment to identify the underlying cause should be undertaken and appropriate modifications

274

P. Sharma and P. Sharma

Fig. 18.50 Peri-­ implantitis affecting maxillary implants displaying significant bone loss

Fig. 18.51 Mechanical complication: fracture of acrylic teeth on mandibular hybrid implant supported bridge

made to help mitigate potential risks from occlusal overload [8]. This may include the need for occlusal reassessment at recall appointments and adjustments as required or in some cases altering the design of the prosthesis. Parafunctional habits (clenching or grinding) can transmit forces to the supporting bone that may result in destructive lateral stresses and overloading. The consequences of nocturnal parafunctional habits may be prevented by acrylic resin night guards [22]. Figure 18.52 shows an example of a maxillary acrylic resin guard. Such a night guard contributes to optimally distributing and vertically redirecting forces that go with nocturnal tooth grinding and clenching [23]. A night guard that promotes even occlusal contacts around the arch in centric-related occlusion can be helpful to prevent fractures of implant prostheses (Chaps. 11 and 19).

18  Dental Implants in the Management of Tooth Wear

275

Fig. 18.52  Provision of a maxillary acrylic resin guard (an ‘occlusal splint’) to protect extensive maxillary and posterior mandibular implant reconstructions

18.8 Conclusion Tooth wear can be generalised or localised and occur as a result of erosion, attrition and abrasion. The aetiology of tooth wear caused by attrition is multi-factorial however bruxism and parafunction play a significant role. Whilst a multitude of restorative approaches are available to manage these patients, dental implants can be essential in some patients to achieve satisfactory function, aesthetics and occlusal stability. Few studies have focused on approaches to protect implant restorations from bruxism and further research in this area is required. Many clinicians still believe that overload from bruxism may result in failure of implant supported prostheses. Taking all of this into consideration, this chapter has highlighted the necessity for accurate assessment, treatment planning, prosthetic design, occlusal control and long-term maintenance, in an effort to increase the predictability of dental implant restorations in tooth wear patients.

References 1. Moraschini V, Poubel LA, Ferreira VF, Barboza ES. Evaluation of survival and success rates of dental implants reported in longitudinal studies with a follow-up period of at least 10 years: a systematic review. Int J Oral Maxillofac Surg. 2015;44:377–88. 2. Laura G, Salcido JP, Guda T, Ong JL. Current trends in dental implants. J Korean Assoc Oral Maxillofac Surg. 2014;40:50–60. 3. Alghamdi HS, Hamdan S.  Methods to improve osseointegration of dental implants in low quality (Type-IV) Bone: an overview. J Funct Biomater. 2018;9:1–9. 4. Zitzmann NU, Margolin MD, Filipp A, Weiger R, Krastl G. Patient assessment and diagnosis in implant treatment. Aust Dent J. 2008;53(Suppl. 1):S3–S10. 5. Chrcanovica BR, Albrektsson T, Wennerberga A. Smoking and dental implants: a systematic review and meta-analysis. J Dent. 2015;43:487–98. 6. Bragger U, Aeschlimann S, Burgin W, Hammerle CHF, Lang NP.  Biological and technical complications and failures with fixed partial dentures (FPD's) on implants and teeth after four to five years of function. Clin Oral Implants Res. 2001;12:26–34. 7. Engel E, Gomez-Roman G, Axmann-Krcmar D.  Effect of occlusal wear on bone loss and periotest value of dental implants. Int J Prosthodont. 2001;14:444–50.

276

P. Sharma and P. Sharma

8. Komiyama O, Lobbezoo F, De Laat A, Iida T, Kitagawa T, Murakami H, Kato T, Kawara M.  Clinical management of implant prostheses in patients with bruxism. Int J Biomater. 2012;4:1–6. 9. Berglundh T, Persson L, Klinge B.  A systematic review of the incidence of biological and technical complications in implant dentistry reported in prospective longitudinal studies of at least 5 years. J Clin Periodontol. 2002;29:197–212. 10. Johansson T, Jemt T. Implant treatment in the edentulous maxillae: a 15-year follow-up study on 76 consecutive patients provided with fixed prostheses. Clin Implant Dent Relat Res. 2006;8:61–9. 11. Block MS. Techniques for grafting the extraction socket. 2nd ed. Oxford: Elsevier; 2007. 12. Warreth A, Ibieyou A, Bernard O'Leary R, Cremonese M, Abdulrahim M. Dental implants: an overview. Dent Update. 2017;44:596–620. 13. Warreth A, Fesharaki H, McConville R, McReynolds. An introduction to single implant abutments. Dent Update. 2013;40:7–17. 14. Newsome P, Reaney D, Owen S.  Screw- versus cement-retained crowns. Irish Dentist. 2011:22–5. 15. Warreth A, Byrne C, Alkadhimi AF, Woods E, Sultan A. Mandibular implants supported overdentures: attachment systems, and number and locations of implants—Part II. J Ir Dent Assoc. 2015;61:144–8. 16. Jivraj S, Chee W, Corrado P.  Treatment planning of the edentulous maxilla. Br Dent J. 2006;201:139–52. 17. Henry PJ.  A review of guidelines for implant rehabilitation of the edentulous maxilla. J Prosthet Dent. 2002;87:281–8. 18. Roberts WE, Kj M, Mozsary PG.  Rigid Endosseous implant used as anchorage to protract molars and close anatrophic extraction site. Angle Orthod. 1989;60:135–51. 19. Sakka S, Baroudi K, Nassani MZ.  Factors associated with early and late failure of dental implants. J Investig Clin Dent. 2012;3:258–61. 20. Lang NP, Berglundh T. Periimplant diseases: where are we now? Consensus of the Seventh European Workshop on Periodontology. J Clin Periodontol. 2011;38(Suppl. 11):178–81. 21. Derks J, Tomasi C. Peri-implant health and disease. A systematic review of current epidemiology. J Clin Periodontol. 2015;42:158–71. 22. Derks J, Tomasi Tosun CT, Karabuda C, Cuhadaroglu C. Evaluation of sleep bruxism by polysomnographic analysis in patients with dental implants. In J Oral Max Impl. 2003;18:286–92. 23. Lobbezoo F, Brouwers JEIG, Cune MS, Naeije M. Dental implants in patients with bruxing habits. J Oral Rehabil. 2006;33:152–9.

Prevention, Maintenance and Dealing with Failures

19

Judith Wickens

19.1 Introduction Awareness of tooth wear affecting all age groups has increased among both dentist and patient over the last 30 years; other diseases of teeth are better controlled with many more people remaining partially or fully dentate into old age [1]. The prevalence of tooth wear across the population is now published in longitudinal studies [2], warning us to not only consider it a disease of advancing years but to pay attention to the existence of severe erosive tooth loss as early as the adolescent years (Chaps. 2 and 12). Social media has also been increasingly influential in patients’ awareness of their appearance. These factors have led to a shift in patient expectations that is driving a change in the daily practice of clinical dentistry. It is accepted that caries and periodontal disease can be controlled with appropriate education and professional support, even in the older patient. In contrast, the dental profession is slow to accept the same level of monitoring and action in patients with active tooth wear. Earlier chapters have highlighted the multifactorial aetiology of tooth wear, how to address them with the support of dental and medical teams and the complexities of management of the dynamic effects of tooth wear. The ways that tooth wear is monitored as well as the methods and materials used to restore tooth wear may all be open to preference but there is a single recurrent and over-riding theme: that prevention of tooth wear is preferable to restoration. The latter will often be extensive, expensive [3] and carries with it a lifetime commitment to maintenance and further restorative procedures.

J. Wickens (*) Private Practice, Isle of Wight, Cowes, UK © Springer Nature Switzerland AG 2022 A. Eder, M. Faigenblum (eds.), Tooth Wear, BDJ Clinician’s Guides, https://doi.org/10.1007/978-3-030-86110-0_19

277

278

J. Wickens

19.2 Prevention Prevention relies on identification of those individuals who may be at risk (Chap. 3). Predictors such as an increase in age, incisal wear, vertical overbite and incisal occlusion [4] help the profession with this identification. Tooth wear may begin in the primary dentition and there is evidence of a link between this and continued tooth wear in the permanent dentition; for example, horizontal wear of maxillary anterior teeth at 14 years of age is a sound predictor of continuing wear of these teeth at 18 years of age [5]. Other factors, such as maximal anterior bite force, intake of low pH foodstuffs and a low gonial angle, correlate well with the total area of wear on the anterior teeth. These features, along with the knowledge that the number and distribution of teeth with occlusal wear increase with age [2], would imply that once wear begins, it continues at a steady pace. The literature, though, does not support this. Tooth wear can occur in ‘bouts’ as habits and morphological/psychological states change; for example, bruxism in children generally increases with age through the mixed dentition and then decreases [6]. A further complication for the profession is that while the dominant aetiological factor in the patient may have diminished, the affected teeth will have been altered to render them more susceptible to other factors in the process of tooth wear, such as erosion due to dietary acids. The diagnosis is, therefore, complex and further highlights the need for comprehensive and broad-based patient education. Effective Prevention of Tooth Wear Should Include:

• • • • •

Early recognition by the profession Appropriate referral to other professions and dental disciplines [7] Use of predictors [1, 2] (Chap. 3) Patient education by the dental team [8] Use of recording methods to communicate change: indices, photographs, casts, 3D imaging [9] • Control of further tooth wear by modification of habits • Protection of tooth surfaces from the causative factor • Review by the dental team at suitable intervals to maintain patient motivation Communication is also important in the prevention of pathological or accelerated tooth wear. Careful questioning regarding dietary, gastric or parafunctional habits may indicate the reasons for the state of the dentition. Adults who report parafunctional activity are known to have more incisal and occlusal tooth wear than those unaware of a grinding habit [10]. It has been suggested that tooth grinding is a motor disturbance that is not limited to the masticatory muscles but also manifests itself as generally increased body movement [11]. Respected institutions advertise clinics for nocturnal bruxism with sleep disorders. Two aetiological models have been developed; a structural model based on the role played by any malocclusion or alteration in the maxillo-­mandibular relationship and a rather more functional model

19  Prevention, Maintenance and Dealing with Failures

279

which highlights the role of stress, emotional tension and personality characteristics [12]. However, there is no cause-and-effect relationship established in longitudinal studies to give any predictive value to either of them. Nocturnal bruxism occurs in about 13% of the population [13]. Factors Increasing the Risk of Tooth Wear:

• • • • •

Tooth wear as a child Reported parafunctional activity Heavy anterior bite force, possibly related to a low gonial angle Eating disorders, including the excessive intake of low pH beverages Medical disorders resulting in gastric reflux or voluntary vomiting

The ability to use such information depends on the patient reporting aspects of their own behaviour which even they may not consider relevant to their dental problems. As a result, assessment of the teeth may reveal the first indication of an abnormal habit or disease. Bartlett highlighted this when he showed that 17 of 26 patients presenting with tooth wear on the palatal aspect of their maxillary anterior teeth had unreported or undiagnosed daytime gastro-oesophageal reflux [14]. This illustrates just one of the fundamental difficulties for the professional team in determining the cause of the tooth wear which could impact negatively on a suitable referral or education for the patient.

19.3 The Importance of Prevention The effects of tooth wear may not simply be limited to wear of the teeth as it can also affect the surrounding structures. Teeth try to maintain functional contact, both occlusally and inter-proximally [15] and tend to move as they wear. Alveolar bone and the periodontal complex move with the teeth, such that the congruity of the gingival margin will often indicate where there has been tooth movement. Figure  19.1 shows the localised effect of retaining an increasingly worn primary tooth, with the result that the opposing and adjacent teeth have encroached on the a

b

Fig. 19.1 (a and b) The localised effects of retaining a primary tooth

280

J. Wickens

space required for an aesthetic or functional replacement. Treatment for this adult has been complicated by a lack of earlier management of tooth wear. Similarly, tooth wear caused by parafunctional activity is frequently accompanied by compensatory changes in the dentition that allow occlusal contacts and function to be maintained. Tooth wear in the anterior segment of the mouth is often unsightly, driving the patient to seek professional advice. It will commonly have been accompanied by a change in the occlusal relationships which may have functional implications and complicate restorative procedures. Attempts are frequently made to meet the aesthetic demands of patients without due consideration of the functional challenges which can result in either failure of the restorations or wear of the opposing teeth due to inappropriate loading. However, patients may delay seeking help until gross changes, such as facial asymmetry (Fig.  19.2), have taken place. Investigation of the patient’s maxillo-­ mandibular relationship in the retruded position revealed an underlying skeletal discrepancy of the dental bases producing an edge-to-edge tooth relationship. A functional ‘best fit’ had been assumed and tooth wear had resulted from parafunctional activity in this position. Earlier recognition might have prevented compensatory tooth movement and simplified corrective treatment. Prevention of further tooth wear ideally involves elimination of the cause but this simple action is often impossible. A preventive regime with features common to all patients can be developed which aims to modify habits and protect the remaining tooth structure. This should be provided by the dental team and includes: • Patient education and reiteration of the insidious changes that occur • Dietary and toothbrushing advice (technique and timing of brushing) • Use of chemical adjuncts: fluoride dentifrice, mouthwash and varnish (patient and/or professional application) • Careful monitoring of tooth wear (use of indices, photos [16], serial casts (Fig. 19.3) and 3D scanning [7]) Additional and rather more specific actions may be recommended to address any dominant aetiological factors, such as: • Parafunctional activity, constant or phasic in nature: will require the provision of an appropriate protective occlusal splint (Chap. 11). • Extrinsic erosion: fluoride toothpaste, varnish, rinses and CPP ACP toothpaste [17]; the latter supersaturates the hydroxyapatite crystals with bio-available calcium and phosphate ions, limiting demineralisation and promoting remineralisation (Chap. 6). • Intrinsic erosion: An integrated approach with medical colleagues is recommended in cases of voluntary vomiting and suspected gastro-oesophageal reflux [7].

19  Prevention, Maintenance and Dealing with Failures

a

281

b

c

d

Fig. 19.2 (a–d) Tooth wear presenting as a case of gross facial asymmetry

19.4 Restorative Intervention The timing and nature of restorative intervention is influenced by many parameters, not least the patient themselves but also the skill set of the professional team. On the one hand, the simple, conservative placement of adhesively-retained plastic restorative materials in erosion lesions (Fig. 19.4) may be considered a valuable part of preventive or restorative care. They are straightforward to maintain and, in areas not susceptible to high loads, they have an excellent retention rate [18] and should be used to repair and protect the surfaces of teeth in a quick and efficient manner. On the other hand, signs and symptoms may drive the need for restorative care but may also simply be evidence of active tooth wear. More importantly, the dental team

282

J. Wickens

a

b

c

d

Fig. 19.3 (a) Labial view and (b−d) serial study casts recorded over a period of 17 years showing the value of comparative casts to monitor the progression and extent of tooth wear

must be alert to wear which causes no symptoms and ensure that preventive regimes are well established. Successful prevention, though, will be dependent upon an appreciation by the patient of the long-term benefits of such regimes. A team approach, using the hygienist to regularly reinforce the modification of habits, will assist with this difficult task of sustained motivation. Without intervention, the number and distribution of teeth with incisal and occlusal wear will increase with age [2]. Indications for Intervention

• Tooth wear or the failure of existing restorations is becoming detrimental to the patient’s oral health and the stability of the dentition. • Signs or symptoms from the teeth become unacceptable to the patient; these may not only include pain and sensitivity but also a deterioration in the appearance of the teeth.

19  Prevention, Maintenance and Dealing with Failures

a

283

b

Fig. 19.4 (a and b) The placement of plastic restorations in erosion lesions may be considered an essential part of preventive restorative care

Restoration or replacement of teeth in dentitions with worn functional surfaces using traditional or contemporary methods presents three main challenges, all of which have been covered in previous chapters: 1. The functional relationship of the teeth will have changed. The occlusal table is widened bringing a broader aspect of the tooth into function, generating broad, flat occlusal contacts which lack of stability, unfavourable loads (Chap. 11) and stress on interfaces. 2. A physical reduction in crown height. Generating space for restorative materials will remove even more tooth unless an increase in the occlusal vertical dimension is to be considered. Any compromise in material thickness will undermine physical attributes of the material whilst retention and resistance form for conventional fixed prosthodontics will be reduced tempting reliance on chemical bonding rather than physical retention for successful outcomes. The predictability and longevity of removable prostheses may also be negatively impacted if material requirements are compromised. 3. The quality of the remaining worn tooth structure, with exposure of large areas of dentine, may limit the success of preferred conservative adhesive techniques. Pragmatic and predictable approaches to care planning are key (Chaps. 9 and 10) to the successful management of patients with tooth wear. Their provision requires

284

J. Wickens

consent (Chap. 8) and this is based on a level of knowledge from the professional that explains the range of options; from doing nothing to providing complex restoration. The longevity of restorations underpins our ability to provide appropriate care but the literature is not conclusive in its evaluation of factors that influence the lifespan of restorations; it tends to focus on material failure rather than the situation. Of those that reflect provision in the worn dentition [19], annual failure rates are given for each material which are highly variable. This fails to guide the dentist who aims to provide predictions for the patient about longevity, perhaps over a lifetime. There is no strong evidence in published systematic reviews that supports the use of one material over another; direct or indirect materials may be feasible options to restore severely worn teeth [16, 19, 20]. The European Consensus Statement on management of cases with severe tooth wear, published in 2017, recommends that when intervention is recommended and agreed, a conservative, minimally invasive approach using adhesive technology is used [21]. The caveat remains in many papers that all restorations in cases of accelerated wear of the functional surfaces of the teeth (or implant restorations) should be controlled with a protective mouthguard. Where such removable prostheses are worn, an additional or replacement appliance can be provided with the same performance assumed of a splint provided for a dentate patient. This prolongs the life of the prosthesis and teeth but, most importantly, helps to reduce differential wear of materials and overload of the remaining, often fragile, dentition (Chap. 11).

19.5 Longevity The survival of restorations in the oral environment has been widely reported; caries and marginal degradation are cited as the two most common reasons for failure of restorations [22]. However, this view is simplistic. For example, the stresses applied to the cement film retaining an indirect restoration may in the end cause the lute to begin to disintegrate. This allows leakage and eventually dental caries may develop. The primary cause of failure is not the decay but instead the factors that caused the cement to disintegrate. Worn dentitions are frequently ‘patched’ and repaired with adhesively-retained composite resins or glass ionomer cements as the defects often do not lend themselves to conventional cavity preparation. Deterioration and failure of such restorations can contribute to a loss of occlusal stability which may be further compounded by ongoing tooth wear. Whenever possible, minimal preparation and adhesive technology is recommended. Whilst material selection is not believed to be critical to outcomes in controlled studies, the ability of the operator may have a profound effect on successful treatment outcomes for the patient [23]. Modern technologies streamlining digitally produced restorations are proclaimed to be suitable for cases of tooth wear [24] but if the dentist does not have the required clinical skills, these assets will not benefit the patient; execution requires confidence in controlling the oral environment under

19  Prevention, Maintenance and Dealing with Failures

285

Fig. 19.5  Sectional die of a preparation for a ceramic restoration

rubber dam, selection of correct material combinations and allocation of appropriate appointment times. These cannot possibly be gained at undergraduate level alone and require continuing education based on sound restorative dental principles. By way of example, whilst Fig. 19.5 shows a sectional cast with a die of a molar tooth prepared for an adhesively-retained ceramic restoration; there may well be a circumferential ring of enamel for bonding [25] but if there is no control of functional load, nor resistance or retention form, nor adequate isolation at the time of fit, early failure can be anticipated.

19.6 Dealing with Failures Most restorations will, at some point, benefit from maintenance; if not, they will ultimately fail biologically, mechanically or aesthetically. Dealing with such a restorative failure is never easy and a logical two-step sequence for assessing and managing the problem is recommended to stabilise the situation: Step 1: assessment • Identify signs and symptoms on presentation (e.g. pain, mobility or fracture of tooth or restoration, unacceptable appearance) • Assess contributing factors (e.g. active tooth wear, unstable occlusal environment, unsatisfactory technical standards, active dental disease) • Assess and, if indicated, modify the occlusal environment • Assess and protect the remaining tooth structure with minimal intervention where possible Step 2: management • Review and plan future restoration • Provide the definitive restoration • Prevent further damage through preventive regimes

286

J. Wickens

Fig. 19.6  Failure of amalgam restoration in the mandibular right second premolar with compomer repair

Restorative failures today will often reflect tooth or material failure (Fig. 19.6) and techniques or designs advocated many years ago may no longer be current concepts. The ability to manage these remains important in daily general practice. Moving to a more complex situation, Fig. 19.7 shows a failed bridge with secondary caries and periapical pathology associated with the retainers. To deal with these problems, the sequence described above was followed. This bridge was of a complex design with multiple, rigidly-linked retainers; the cement lute had been stressed and failed. A simpler design, incorporating a removable prosthesis or implants, would be advocated if the restoration were to be remade. However, initially, the bridge was removed (Fig.  19.7b), the remaining teeth evaluated and the bridge relined and replaced as a temporary measure (Fig.  19.7c). The dynamic occlusion was reassessed as wear, or loss, of the molar teeth will have altered loads on the restoration. This stabilised interim situation has given the patient and the dental team maximum gain for minimum expense. No definitive care has been provided and all options remain open for discussion, planning and consent. Reparative dental treatment and future planning for definitive care can then be undertaken in a comfortable, controlled environment with an involved and satisfied patient.

19  Prevention, Maintenance and Dealing with Failures

a

c

287

b

d

e

Fig. 19.7 (a−e) Failure of a complex bridge with secondary caries and periapical pathology associated with the abutment teeth

The occlusal examination is important when there is a restorative failure that is not clearly related to caries or periodontal disease. Any treatment provided in the assessment or emergency appointment may not be as physically robust as the original, whether it be as described above or tightening an implant screw or rebonding to a previously bonded surface as just some examples. As such, the dynamic loads need to be controlled for survival of the interim restoration whilst the occlusal assessment is ongoing as outlined below: • Check occlusal stability and note any changes which might have influenced failure such as recent loss of teeth, further wear or replacement of restorations. • Look for wear facets on the opposing dentition. • Check all excursive pathways of mandibular movement and ascertain whether there was adequate space for the restoration. If not, it may be an indication that

288

J. Wickens

the restoration itself was an interference. Such an interference can often be removed by modification of the preparation or the opposing tooth. Where it was a guiding surface, consideration should be given to distributing these loads more widely. Any adjustments are, however, best planned on a set of articulated study casts prior to being done in the mouth. Only those adjustments that can be accomplished simply and predictably should be completed without extra-oral planning.

19.7 Control of the Aetiological Factors Human nature suggests that a patient will comply with requests to modify their habits for a limited time period and normally only whilst under professional review. As a result, reviews should be at intervals that are sufficiently short to keep the patient motivated and allow the whole dental team to be involved. It is unlikely that all the aetiological factors causing the tooth wear will have been identified or controlled. For example, patients who demonstrated parafunctional activity at the time of initial presentation will be at high risk of continued parafunction. In Fig. 19.8, the worn palatal surfaces of the maxillary anterior teeth in this teenager had been protected with adhesively-retained metal palatal veneers. Both the patient and clinician were concerned that the opposing mandibular anterior teeth would be at risk of further wear. The patient was, therefore, provided with a hard acrylic maxillary occlusal splint for night use (Chap. 11) and an annual recall programme was considered appropriate. The dentist-hygienist team is extremely important in the recall strategy with the hygienist seeing the patient more regularly and able to alert the dentist to obvious changes to tooth contour and any concerns expressed by the patient. Figure 19.9 shows a worn dentition that has been restored with indirect restorations in the posterior quadrants. The occlusal environment at that time provided appropriate anterior guidance with posterior disclusion. Whilst a hard acrylic maxillary occlusal splint was provided post-restoratively for night use, by the patient’s own admission compliance was poor. The result has been continued wear of the canine teeth, with shallowing of the anterior guidance to such an extent that, as a a

b

Fig. 19.8 (a and b) An occlusal splint to be worn at night in a case of suspected tooth wear secondary to parafunctional activity

19  Prevention, Maintenance and Dealing with Failures

a

b

c

d

e

f

289

Fig. 19.9 (a−f) A worn dentition restored with indirect restorations in the posterior dentition

result, the posterior teeth are in contact throughout lateral excursive movements. The gold restorations have become worn and occlusal stability has been lost. This expensive restorative procedure has been undermined by a lack of compliance with preventive regimes. It highlights the care needed in matching restorative care with

290

J. Wickens

the needs, wishes and abilities of the patient. Patient involvement in the planning of such care must be comprehensive and any definitive care plans should not be finalised until a thorough period of evaluation has been completed.

19.8 The Recall Appointment Building upon earlier comments, each patient should have a personalised recall programme within their comprehensive oral health care plan. The intervals should be based on an individual risk-assessment to review at least the following: caries, periodontal disease, oral hygiene, oral cancer and tooth wear. For most patients, dentist reviews will be at 6–12 month intervals and hygienist visits will be at 3–12 month intervals. In addition to any treatment that may be necessary at the same visit, the routine for the dental team at recall visits should involve a listen, look and learn approach as outlined below. Listen: an initial general conversation with the patient may indicate whether the original aetiological factors involved in the tooth wear are under control. It is also important to consider the patient’s views: for example, if they think that their splint is a social barrier, it may not be worn regularly and major life events may also affect their ability to carry out normal daily routines. As a result, reasonable and achievable changes may need to be made in consultation with the patient. Look: whilst the intra-oral examination may support aspects of the history, comparison of the current situation with previous sets of study casts (Fig.  19.3) and photographs is essential. These casts and photographs can either be held by the dentist as part of the patient’s records and/or be the property and responsibility of the patient to encourage ownership of the problem. These visual stimuli—such as study casts, photographs and more recently 3D images—are of greater value to the patient at recall when compared to tooth wear indices which can lack sensitivity to change and can be confused by tooth loss and may fail to demonstrate the dynamic nature of tooth wear processes. Monitoring tooth wear is demanding and the frequency of professional re-­ evaluation must be appropriate to that individual and any changes must be recorded [26], not only to monitor preventive regimes but also to be able to make an informed decision regarding the need for, and timing of, restorative intervention. For those patients who have already been restored, further complications may arise and close monitoring is essential. Marginal deficiencies related to all indirectly fabricated restorations are filled at cementation with soluble, permeable cements, whether of acid-base or resin variety. Detection of marginal gaps is often very difficult, especially when margins are inaccessible, and radiographs can be an invaluable additional tool. Posterior composite resins must be radio-opaque to allow this simple, repeatable monitoring. Tooth wear grading documents as highlighted by Wetselaar et al, or similar, can be helpful in recording tooth wear and any changes and held as part of the patient’s records for future comparison [26]. It may also be necessary to address the following signs and symptoms commonly seen in patients with tooth wear (Fig. 19.10):

19  Prevention, Maintenance and Dealing with Failures

291

Fig. 19.10  Patient presenting with sensitivity from the mandibular left second molar yet many teeth show signs of significant tooth wear at 60 years of age, resulting in an unstable occlusal environment with lack of predictability in outcomes for both patient and dentist

Fig. 19.11  Incisal tooth wear left unaddressed has resulted in altered occlusal loading on Class III restorations in the mandibular left central incisor which have failed

• Pain and sensitivity: these may serve as predictors that tooth wear is ongoing and occurring faster than any reparative mechanisms. • Sharp edges of tooth or restoration (Fig. 19.11). • Facets on tooth or restorative material. Learn: as dental professionals, we are able to develop a respected position of trust with our patients. Despite many papers on material selection and their

292

J. Wickens

outcomes, no longitudinal studies exist to support our recommendations to patients. Whilst most patients wish to remain dentate for the rest of their lives, those who demonstrate significant tooth wear, often significantly in advance of their chronological age, will always challenge our abilities. The professional team must apply sound principles of restorative dentistry [27, 28] to ensure that their skill set matches their provision of irreversible procedures. Alongside this, and through careful engagement in assessment, diagnosis and care planning, each and every patient must accept responsibility for their part in controlling the multifactorial challenge of tooth wear.

19.9 Conclusion Whilst many treatment options are available for patients to consider and for dentists to provide, complex care may need to be delivered by specialists in practice or in secondary referral centres. Wherever and whenever care is to be provided and by whom, careful thought needs to be given to planning for failure which could, for example, be catastrophic if vertical fracture of a key abutment tooth and may lead to tooth removal and re-planning of a new or larger restoration. Figure 19.12 highlights the presence of slot in the distal of the maxillary left canine and guide planes on the palatal surfaces that can be used in the future for retention of fixed or removable restorations when the post-retained crown on the adjacent premolar fails. Strategic planning that identifies, and then relies upon, longevity of restorations is commendable but not fool proof. Planning for the inevitable failure typifies a reflective clinician who is able to think and plan ahead by incorporating features that can facilitate a continuity of care with minimal disruption to other teeth or restorations whilst keeping the number of abutments to a minimum. Whether on natural teeth or implants, managing the occlusal load—or controlling the occlusal overload—remains key to success.

Fig. 19.12  The provision of a ‘sleeping slot’ in the distal surface of the maxillary right canine and guide-planes can both assist with the future design of alternative restorations

19  Prevention, Maintenance and Dealing with Failures

293

References 1. NHS Digital Adult Dental Health Survey 2009—Summary report and thematic series [NS] London: The Health and Social Care Information Centre; 2011 [https://digital.nhs.uk/ data-­and-­information/publications/statistical/adult-­dental-­health-­survey/] 2. Wetselaar P, Vermaire JH, Visscher CM, Lobbezoo F, Schuller AA. The prevalence of tooth wear in the Dutch adult population. Caries Res. 2016;50:543–50. 3. Slater L, Eder A, Wilson N. WORNing: tooth wear ahead. Prim Dent J. 2016;5(3):38–42. 4. Silness J, Johannessen G, Roynstrand T. Longitudinal relationship between incisal occlusion & incisal tooth wear. Acta Odontol Scand. 1993;51(1):15–21. 5. Nystrom M, Kononen M, Alaluusua S, Evalahti M, Vartiovaura J.  Development of horizontal tooth wear in maxillary anterior teeth from five to eighteen years of age. J Dent Res. 1990;69:1765–70. 6. Cash R. Bruxism in children; a review of the literature. J Paedodont. 1988;12:107–27. 7. Ahmed E.  Management of tooth wear: a holistic, dental, medical, and mental healthcare approach. Prim Dent J. 2016;5(3):35–7. 8. Ariyanayagam Y. A dental hygienists and therapists guide to the management of tooth erosion. Prim Dent J. 2016;5(3):58–62. 9. Hemmings K, Truman A, Shah S, Chauhan R. Tooth wear guidelines for the BSRD Part 1: Aetiology, diagnosis and prevention. Dent Update. 2018;45:3–10. 10. Ekfeldt A, Hugoson A, Bergendal T, Helkimo M. An individual tooth wear index and an analysis of factors correlated to the incisal and occlusal tooth wear in an adult Swedish population. Acta Odontol Scand. 1990;48:344–9. 11. Sjoholm T, Polo O, Alihanka A. Sleep movement in tooth grinders. J Craniomandib Disord. 1992;6:184–91. 12. Biondi M, Picardi A.  Temporomandibular joint pain dysfunction syndrome and bruxism: aetiopathogenesis and treatment from a psychosomatic integrative point of view. Psychother Pychosomatic. 1993;59:84–98. 13. Yap A, Chua AP. Sleep bruxism: current knowledge and contemporary management. J Conserv Dent. 2016;19(5):383–9. 14. Bartlett D, Evans D, Smith B. Simultaneous oral and oesophageal pH measurement after a reflux provoking meal. J Dent Res. 1994; Spec Issue Abst.70 15. Love W, Adams R. Tooth movement into edentulous areas. J Prosthet Dent. 1971;25:271–8. 16. Milosevic A. Direct placement composite; the treatment modality of choice to restore the worn or eroded dentition in primary dental care. Prim Dent J. 2016;5(3):25–9. 17. Green IJ. Prevention and management of tooth wear: the role of dental technology. Prim Dent J. 2016;5(3):30–3. 18. Brandau HE, Ziemiecki T, Charbeneau G. Restoration of cervical contours on non-prepared teeth using glass ionomer cement; a 4-year report. J Am Dent Assoc. 1984;108:782–3. 19. Mesco ME, Sarkis-Onofre R, Cenci MS, Opdam NJ, Loomans B, Pereira-Cenci T. Rehabilitation of severely worn teeth: a systematic review. J Dent. 2016;48:9–15. 20. Loomans BAC, Kreulen CM, Huijs-Visser H, et al. Clinical performance of full rehabilitations with direct composite in severe tooth wear patients. J Dent. 2018;70:97–103. 21. Loomans B, Opdam N, Atytin T, et al. Severe tooth wear; European Consensus statement on management guidelines. J Adhes Dent. 2017;19(2):111–9. 22. Good J. Survival analysis of indirect restorations in extensively restored dentitions. Eastman Dental Institute, University of London, MSc Report; 1996. 23. Burke T, McKenzie L, Shorthall A. Survival rates of resin composite restorations in loadbearing situations in posterior teeth. Dent Update. 2019;46(6):524–36. 24. Hyeonjong L, et al. Virtual diagnostics and guided tooth preparation for the minimally invasive rehabilitation of a patient with extensive tooth wear: a validation of a digital workflow. J Prosthet Dent. 2020;123:20–6.

294

J. Wickens

25. Mizrahi B. Combining traditional and adhesive dentistry to reconstruct the excessively worn dentition. Eur J Esthet Dent. 2008;3(3):270–89. 26. Wetselaar P, Wetselaar-Glas MJM, Katzer LD, Ahlers MO. Diagnosing tooth wear, a new taxonomy based on the revised version of the Tooth Wear Evaluation System (TWES 2.0). J Oral Rehabil. 2020;47(6):703–12. 27. Schaerer P, Rinn L, Kopp F, et al. Esthetic guidelines for restorative dentistry. Quintessence Pub Co.; 1982. 28. Shillingburg H, Hobo S, Whitsett L, Jacobi J, Brackett S. Fundamentals of fixed prosthodontics. Quintessence Pub Co.; 2012.

Tooth Wear: Future Considerations Andrew Eder and Maurice Faigenblum

Abstract The dental literature reflects an increasing interest in tooth wear and this latest edition not only covers the clinical aspects of prevention and caring for patients with tooth wear but also focuses on the science of wear and highlights the shift toward minimally invasive approaches to care. However, the challenge of deciding when it may be best to intervene restoratively remains, as this inevitably leads to a lifetime of care. As a result, the corresponding challenges of capacity and capability with regard to an appropriately trained generalist and specialist workforce as well as funding for prevention and treatment must all be considered. Finally, comprehensive and holistic approaches to care are encouraged to inform and assist all dental professionals and students in their provision of the most appropriate and timely care for patients with tooth wear.

Raising Professional and Public Awareness Tooth wear is an insidious condition that is best identified, and then prevented, in its early stages. However, this begs the question as to who is expected to recognise the early signs (Chap. 2). According to O’Hara and Millar [1], dentists may not always be aware of the current guidelines but do make reasonable attempts to monitor tooth wear (Chap. 8). Patients on the other hand are often blissfully unaware of the early changes as their teeth become worn and may in fact find the smooth and shiny surfaces as being aesthetically pleasing [2]. It is, therefore, incumbent on dental professionals to bring these retrograde effects to the attention of the patient, to monitor changes and provide appropriate care.

A. Eder (*) UCL Eastman Dental Institute and Harley Street Dental and Implant Clinic, London, UK e-mail: [email protected] M. Faigenblum (*) UCL Eastman Dental Institute, London, UK e-mail: [email protected] © Springer Nature Switzerland AG 2022 A. Eder, M. Faigenblum (eds.), Tooth Wear, BDJ Clinician’s Guides, https://doi.org/10.1007/978-3-030-86110-0

295

Tooth Wear: Future Considerations

296 Fig. A.1  Severe tooth wear in a middle-­ aged male

Table A.1 Comparing (MedLine/PubMed) Dental aesthetics Tooth whitening Adhesive dental materials Tooth wear Dental caries

peer

reviewed

publications

1970–1995 4080 526 3838 2067 20,085

for

1970–1995

1996–2021 14,735 3091 19,251 5794 34,047

and

1996–2021

% Increase 261% 488% 402% 180% 70%

The dental world has changed since publication of the first edition of this book in 2000. Then, it was not uncommon to see patients (usually middle-aged males) present with severe tooth wear (Fig. A.1) requiring extractions and/or removable overdentures. Comparing the increase in peer-reviewed publications retrieved using the MedLine/PubMed search term ‘bruxism’ between 2000 and 2009, Manfredini and colleagues [3] were able to indicate how this topic had grown in importance over this period. Similarly, Table A.1 compares the number of peer reviewed publications over twenty-five-year periods between 1970–1995 and 1996–2021 for (a) dental aesthetics, (b) tooth whitening, (c) adhesive dental materials and (d) tooth wear. The number of publications on (e) dental caries is also given for the same time periods. From the increase in the number of published articles related to dental aesthetics and tooth whitening, it can be surmised that this could be due to the impact of global popular media especially television and social media [4, 5]. Similarly, recent advances in adhesive dentistry (Chap. 16) have allowed general dental practitioners to carry out treatments that were not previously considered or even available. The table also suggests that, over the past 50 years, professional interest in tooth wear has expanded significantly. This expansion has incentivised the advancement of knowledge and application of evidence-based approaches to care for patients with tooth wear. This interest is further reflected by the increase in the number of chapters and specialist authors that have been added to this latest edition. Contrastingly, and as might be expected, the number of publications on dental caries started at a much a higher level but has only seen a gradual increase over the same period.

Tooth Wear: Future Considerations

297

Changing Approaches to Care The successful care of patients with tooth wear requires the correct identification of the primary aetiology, and the underlying cause, at the earliest opportunity to instigate preventive strategies without unnecessary delay. Without this, care may be inappropriate and tooth wear will progress. Unfortunately, identification of the primary aetiology can be difficult and made even more challenging when a multi-­ factorial aetiology exists. Where the protective enamel has already been lost, elimination of the aetiology and preventive measures may not stop future wear of the less hard and unprotected dentine due to abrasion of contacting surfaces during daily function. As a result, preventive strategies and approaches to care need to be reviewed and modified according to ongoing changes that may be seen at reassessment and the following clinical examples highlight the shift toward minimally invasive additive techniques. Challenges in diagnosis, controlling tooth wear and restoration have all been highlighted in the introductory chapter. To make these challenges even more clinically relevant, the following two points are proposed for consideration: 1. The timing of minimally invasive restorative intervention must be balanced against the unnecessary progression of tooth wear which may result in far more complex treatment being required at a later date. 2. Achieving functional and aesthetic treatment outcomes with regard to the availability of inter-occlusal space and material selection. As we, the dental profession, have become increasingly skilled at looking after patients with severe tooth wear, retaining and restoring severely worn teeth (Figs. A.2 and A.3) has become the treatment of choice wherever possible replacing extractions and removable overdentures (Fig. A.1). However, access to such complex and costly care is limited to specialist referral centres, such as dental schools, or where the combination of skill and experience can be delivered by general dental practitioners or specialists in the practice setting.

Fig. A.2  Frontal view showing worn anterior teeth as well as heavily restored and worn posterior teeth

298

Tooth Wear: Future Considerations

Fig. A.3  Frontal view following crown lengthening and restorative treatment with the provision of core fillings for posterior teeth and crowns for all teeth increasing the occlusal vertical dimension and extending the lengths of the anterior teeth. A protective Michigan Splint was provided for night wear to help protect teeth and restorations from parafunctional activity Fig. A.4  Frontal view showing worn mandibular incisors and porcelain bonded to gold crowns restoring previously worn maxillary incisors

Such complex treatments are not without problems. In this second example, the patient shown in Fig. A.4 was bulimic in her early twenties. She was provided with porcelain bonded to gold crowns to restore her maxillary incisors by her general dental practitioner about 20 years ago. Sadly, further removal of tooth tissue will have been necessary to provide these crowns. Five years later, she sought specialist advice to assess the tooth wear involving the maxillary canines and premolars, hoping to avoid more crowns. Timing was good as approaches to care were changing with a far greater emphasis on education and prevention with treatment becoming less invasive and more additive due to an increased understanding of the processes of tooth wear alongside advances in adhesive dentistry. For this particular patient, the maxillary canines and premolars (except for the maxillary right second premolar) were severely worn. Further removal of healthy tooth tissue simply to provide crowns was contra-indicated and the missing hard tooth tissue was replaced with adhesively retained white gold palatal veneers (Fig. A.5) about 15 years ago.

Tooth Wear: Future Considerations

299

Fig. A.5  Occlusal view showing porcelain bonded to gold crowns restoring worn maxillary incisors and white gold adhesively retained palatal veneers restoring worn maxillary canines and premolars

Fig. A.6  Frontal view showing differential wear of anterior teeth also noting dento-alveolar compensation of the maxillary left incisors has occurred

Despite good service for about 20 years, the crowns are now starting to fail with the crown restoring the maxillary left lateral incisor needing to be removed and investigated because of clinical signs and symptoms. The risks to the underlying prepared tooth are high. Contrastingly, if any of the palatal veneers become detached, they can normally be re-fitted with the remaining tooth tissue being intact. Over the past 15–20 years, adhesively retained ceramic and composite resin restorations have seen tremendous developments. As a result, and as shown in this third example, patients with all levels of tooth wear can benefit. A 35-year-old male presented with localised wear of his maxillary anterior teeth caused by carbonated drinks and parafunctional activity (Fig. A.6). Dento-alveolar compensation had clearly taken place to maintain anterior tooth contact with preferential wear of the maxillary left incisors resulting in disruption of the gingival margin height across the anterior teeth. The patient was keen to achieve the most satisfactory aesthetic and functional outcome with a minimally invasive approach avoiding further removal of healthy tooth tissue (Fig. A.7). It is only in the last 20 years or so that this has been possible with control of the aetiology and instigation of preventive measures at the outset being critical. Whilst a Dahl approach might have been possible here, conventional orthodontics was preferred. This was to first harmonise the gingival margin position due to a high smile line revealing the discrepancy and to then create palatal

300

Tooth Wear: Future Considerations

Fig. A.7  Frontal view following orthodontic treatment, home tooth whitening and restorative treatment with the addition of tooth coloured composite resin to extend the lengths of the maxillary anterior teeth and white gold adhesively retained palatal veneers by way of protection. A Michigan Splint was provided for night wear to reinforce orthodontic retention and help protect teeth and restorations from future parafunctional activity

inter-­occlusal space. Once the orthodontic appliances were removed, home tooth whitening was carried out prior to lengthening the maxillary anterior teeth with adhesively retained composite resin and then protecting the worn palatal surfaces and the composite extensions with white gold palatal veneers. A protective Michigan Splint was also provided for night wear.

Conclusion The journey of this latest ‘Tooth Wear’ textbook spans twenty-seven years. Following the success of a course of evening lectures on the management of tooth wear for dental professionals and students in London in 1995 and 1996, a themed series of articles based on these lectures appeared in the British Dental Journal in 1999. The first edition of ‘Tooth Surface Loss’ brought together these articles and was published in 2000 with a second edition available in 2008. Now, in 2021, this completely revised and expanded ‘Tooth Wear’ textbook is available for all dental professionals and students and focuses on current thinking and available data (Table A.2). The timely release of version 4 of the Delivering Better Oral Health evidencebased toolkit in 2021 has raised the profile of tooth wear alongside dental caries, periodontal diseases, oral cancer and behaviour change [6]. Increasing awareness for all dental professionals, with a focus on risk assessment, is key to early identification, the initiation of prevention and changing behaviour. It is intended that this will improve the quality of life and lessen the burden of caring for patients with tooth wear—both in terms of the severity of tooth wear and the numbers of patients requiring care. Burke’s editorial in Dental Update, also in 2021, focuses on the increasing challenge of tooth wear and further highlights the growing volume of publications [7]. In view of increasing numbers of patients requiring monitoring, prevention and care for their worn teeth, this editorial rightly raises several challenging issues.

Tooth Wear: Future Considerations

301

Table A.2  Tooth wear—current status summary 1. The majority of the population (76% adults, >50% children) have tooth wear 2. Management of dental caries and periodontal diseases is improving 3. As population age profiles increase, more teeth will be retained for longer 4. Tooth wear can impact negatively on aesthetics, function and quality of life 5. Management of severe wear creates a significant health and financial burden 6. Indices are available and useful but a risk assessment tool is also recommended 7. Clinical studies should assess tooth wear markers and monitor interventions 8. Research should focus on stem cell technology and material developments

Table A.3  Ten-point care framework for patients with tooth wear  1. Early recognition is essential—sites (teeth, surfaces) and extent (enamel, dentine)   2. Share knowledge and experience—based on opinion leaders and available dental literature  3. Determine the aetiology(ies)—abrasion, attrition, erosion, abfraction  4. Identify the cause(s)—normally multi-factorial, always think outside the box  5. Adopt a holistic team approach—lifestyle, diet, alcohol, stress, oral hygiene, parafunction  6. SMART goals for change—Specific, Measurable, Attainable, Realistic, Timely  7. Monitor tooth wear—casts, photographs, 3D imaging, chronological vs pathological, risks   8. Know when to refer—simple vs complex, occlusal changes, challenge of space and materials   9. Care strategies—minimally invasive, additive where possible, follows compliance and stability 10. Consider wear as a lifelong challenge—monitor lifestyle, wear, treatment

These include where patients can be cared for (capacity), by whom (capability) and how this care is to be funded (resource models). Moving forward, appropriate levels of training for all dental professionals and students will also need to be appropriately supported to encourage care to be made available by general dental practitioners or specialists in the practice setting as the most cost-effective model. On behalf of all the authors, the editors sincerely hope that this latest edition of ‘Tooth Wear’ will be well received by dental professionals and students across the globe, encouraging a comprehensive and holistic approach to caring for patients of all ages who may be experiencing tooth wear (Table A.3).

References

1. O’Hara M, Millar BJ. Evaluation of the assessment of tooth wear by general dental practitioners. Br Dent J. 2020;228(6):423–8. 2. Goldfarb MB, Hara AT, Hirsh AT, Carvalho JC, Maupomé G. Are dental patients able to perceive erosive tooth wear on anterior teeth? An internet-based survey assessing awareness and related action. JADA. 2020;151(1):10–5. 3. Manfredini D, Ahlberg J, Lobbezoo F. Bruxism definition: Past, present and future. What should a prosthodontist know? J Prosthet Dent. 2021. https://doi.org/10.1016/j.prosdent.2021.01.026. 4. Theobald AH, Wong BJK, Quick AN, Thomson WM.  The impact of the popular media on cosmetic dentistry. NZ Dent J. 2006;102(3):58–63. 5. Rana S, Kelleher M. The dangers of social media and young dental patient’s body image. Dent Update. 2018;45(10):902–10. 6. Office for Health Improvement and Disparities, Department of Health and Social Care, NHS England, NHS Improvement. Delivering better oral health: An evidence-based toolkit for prevention, Version 4. London: OHID, DHSC, 2021. [Available from: https://www.gov.uk/government/ publications/delivering-better-oral-health-an-evidence-based-toolkit-for-prevention. 7. Burke FJT. Editorial comment: treating tooth wear in primary dental care. Dent Update. 2021;48(3):173–6.

© Springer Nature Switzerland AG 2022 A. Eder, M. Faigenblum (eds.), Tooth Wear, BDJ Clinician’s Guides, https://doi.org/10.1007/978-3-030-86110-0

303

Index

A Abfraction, 7 Abrasion, 6–7 Acid etch technique, 187 Acrylic resin, 241 Adhesive metal onlays, 202–203 Adhesive technology case selection, 188 cements, 199 composite resin, 207, 209 digital laboratory stages, 205 gold palatal veneers, 208 occlusal wear anterior tooth wear, 192–197 general vs localised, 191–192 posterior wear, 198–199 partial coverage restorations, 187 putty matrix, 204 restoration of anterior tooth wear, 203–209 restorative materials, 200–203 treatment planning cervical tooth wear, 190 direct vs indirect restoration, 189 site, 189 timing, 189 wax-up, 206 Anorexia nervosa (AN), 48, 51–52 Anterior tooth wear, 192–197 Attrition, 4 Avoidant/restrictive food intake disorder (ARFID), 48 Awake bruxism, 4

Bilateral occlusal frictional keratosis, 32 Bimandibular manipulation, 123 Binge eating disorder (BED), 48, 53 Bone sounding, 171 Bruxism, 4 Bruxists, 131 Buccal frictional keratosis, 33 Bulimia nervosa (BN), 48, 52

B Basic erosive wear examination (BEWE), 93 Basic periodontal exam (BPE), 8 Begg and tip-edge techniques, 182

D Dahl concept, 127, 128, 130, 180, 220–221, 238 Dental erosion, 57–59

C Cariogram, 28 Cemento-enamel junction (CEJ), 74 Ceramic onlays palatal veneers, 203 Cervical tooth wear, 190 Chemical extrinsic and intrinsic tooth wear, 108 Child and adolescent adhesive restorative procedures, 153 aetiology, 154 anterior restorations, 161–162 clinical examination, 155 epidemiology, 154 medical history, 155 permanent dentition, 161 posterior restorations, 162–163 prevention of, 158 primary dentition, 160 restorative intervention, 158, 160 Cobalt-chrome alloy, 242 Compensated tooth wear, 232 Cuspal cupping, 156

© Springer Nature Switzerland AG 2022 A. Eder, M. Faigenblum (eds.), Tooth Wear, BDJ Clinician’s Guides, https://doi.org/10.1007/978-3-030-86110-0

305

Index

306 Dental implantology aesthetic and functional integration, 249 biological failures, 272 contra-indications, 251 implant-abutment connection, 250 macro-mechanical features, 250 mechanical failures, 273–274 micro-mechanical features, 250 osseo-integrated implant, 248 partially dentate patients, 270–271 patient age, 251 patient selection, 250–251 periodontal disease, 252 prosthodontic design bone-implant interface, 253 metal restorations, 253 occlusal vertical dimension, 253 replacing missing teeth fixed implant-supported prosthesis, 266–269 fully edentulous patients, 265–267 partially dentate patients, 260, 263–264 treatment options for, 262 restoratively guided treatment protocol analogue technique, 255 digital technique, 256–257 implant treatment planning, 254 restorations CAD software, 257 timing of implant placement, 255, 258–261 screw-retained porcelain, 248 smoking, 251 surgical placement of, 248 Dental practice setting diagnosis, 95–96 examination and history, 94 management of risk factors, 96–97 medical history, 94 montgomery judgement, 98 record keeping, 100 restorative intervention, 98–99 risk and benefits, 99 second opinion, 100 severity, 94, 95 special tests, 96 strategic approach, 97 Dental sleep disorders chemical (erosive) tooth wear, 83 dental sleep medicine, 84 diagnose tooth wear, 85 GORD, 87 mechanical tooth wear, 83 oral dryness, 86

orofacial pain, 86 OSAS, 87 sleep bruxism, 88–89 Dental sleep medicine, 84 Dentine hypersensitivity defence systems, 73–76 dentine physiology, 72–73 enamel physiology, 72 hydrodynamic theory, 71 prevention, 76–78 Denture bases, 241 DSM-V eating disorders, 52 E Erosion, 4–5 Erosive tooth wear, 41–42, 71 Extrinsic acids, 154 Eye-balling, 128 F Fabrication, 144–146 Feeding and eating disorders anorexia nervosa, 51–52 behavioural and medical complications, 53–55 binge eating, 53 bulimia nervosa, 52 classification, 48–49 diagnostic criteria, 48–49 epidemiology, 48–49 managing patients, 62 mental health, 53–55 oral manifestations of pica, 50 oro-dental features caries and oral microbiology, 59 dental erosion, 57–59 diarrhoea, 57 periodontal disease, 60–61 salivary glands, 59–60 soft tissue lesions, 61 TMD, 62 quality of life, 55–56 rumination disorder, 50, 51 Fixed prosthodontics advanced tooth wear, 218 anterior diagnostic wax-up, 219 corrected mandibular occlusal plane, 222 Dahl concept, 220–221 disrupted occlusal plane, 218 disrupted occlusal planes, 218 effects of, 215–216, 218

Index generalised full mouth tooth wear, 223–227 inter-occlusal space, 213 intra-oral mock-up, 219 localised anterior tooth wear, 219–223 materials and designs for, 227–228 maxillary right central and lateral incisors, 214 over-erupted mandibular mol, 222 palatal abrasions, 214 pre-operative labial view on smiling, 219 severe tooth wear, 218 worn mandibular anterior teeth, 214 G Gastro-oesophageal reflux disease (GORD), 8, 22, 50, 87, 94, 110, 154 Gingival biotype, 169 Gold alloy, 242 H Healthcare, 15 Health-related quality of life (HRQoL), 55 Hypertrophic masseters, 31 Hyposalivation, 43 I Internal connection, 250 K Keratinised gingivae, 170 L Longevity, 284–285 Lucia jig, 123 Lugol’s iodine, 170 M Maxillary anterior teeth, 132 Maxillary hybrid prosthesis, 253 Mechanical extrinsic and intrinsic tooth wear, 108 Medical markers, 30 Metal-based dentures, 241 Mucin-rich unstimulated saliva lubricates, 39 Mylar strips, 202

307 N Nickel-chrome onlays, 163 Non-compensated tooth wear, 232 Non-steroidal anti-inflammatory drugs (NSAIDs), 174 O Obstructive sleep apnoea syndrome (OSAS), 87–88 Occlusal vertical dimension (OVD), 106, 191, 220, 233 Occlusion and splint therapy advantages and disadvantages, 141–144 checking lateral movements, 149 checking protrusive movements, 150 fabrication, 144–146 fitting and adjustment, 146–150 mandibular dysfunction, 139–140 masticatory muscles, 136 monitoring, 150–151 occlusal stability, 137, 138 parafunctional activity, 135 pre-restorative stabilisation, 140 prevention of tooth wear, 139 protection of new restorations, 141 rationale and indications for, 138–139 severely worn mandibular anterior teeth, 140 Onlay denture, 235 Onlay provisional denture, 235 Oral dryness, 86 Oral health impact profile (OHIP), 8 Orofacial pain, 86 Orthodontic mini-implant (OMI), 183, 270 Orthodontic therapy appliances, 182–183 Dahl Concept, 180 dento-alveolar compensation, 183 examination of patient, 181 frontal and maxillary occlusal pre-­ treatment, 184 maxillary and mandibular incisors, 183 maxillary anterior teeth, 183 moderate wear, 179 OMIs, 183–185 restoration of teeth, 180 severe wear, 179 treatment, 181 Ostectomy, 173 Osteoplasty, 173 Overdenture, 235 Overlay denture, 235

308 P Palatal veneers, 202–203 Physical markers, 30 Physiological wear, 105 Pica, 48, 50 Pica and rumination disorders, 49–51 Population oral health epidemiology of, 17–19 health promotion programmes, 16 individualised dietary advice, 16 population advice, 20 prevention of, 20, 22 risk factors for, 19 United Kingdom, 15 Porcelain, 241 Pragmatic philosophy clinical and psycho-social effects, 106 counselling and monitoring, 108–112 diagnosis of, 106–108 lifestyle and dietary habits, 105 restorative intervention dento-alveolar compensation, 114 outcomes of, 116–117 OVD, 114–116 shared decision making, 113 Primary teeth, 153 Prosthetic teeth, 241, 242 R Radboud philosophy, 106 Record keeping, 100 Removable prosthodontics adhesive/conventional fixed prosthodontics, 237–238 complete/partial onlay/overlay dentures, 237, 238 complete/partial overdentures, 234–237 definitive dentures, 239–240 denture bases, 241 diagnostic/provisional appliances, 238, 239 extracting remaining teeth, 234 indications for, 231 laboratory considerations, 240 macro-mechanical and micro-mechanical retention, 242 non-compensated tooth wear, 232 occlusal vertical dimension, 233 prevention and maintenance, 242–243 prosthetic teeth, 241, 242 removable management, 233–234 Restorative intervention, 281–284 Rumination disorder (RD), 48, 50, 51 Ryzophagia, 49

Index S Saliva composition and physical properties of, 38–39 COVID-19, 43 erosive tooth wear, 41–42 in oral health, 39–41 salivary secretion, 37 tests, 42 xerostomia, 43–44 Saliva tests (sialometry), 42 Salivary dysfunction, 42 Salivary secretion, 37 Self-induced vomiting (SIV), 53 Severe maxillary anterior palatal tooth wear, 130 Sjogren’s syndrome, 111 Sleep bruxism (SB), 4, 88–89 Social markers, 31 Surgical crown lengthening (SCL) alveolar crestal bone, 165 anatomical challenges and limitations, 167 bone sounding, 171 gingival biotype, 169 gingival outline, 169 gingival tissue, 165 keratinised gingivae, 170 occlusal vertical dimension, 165 ostectomy vs. osteoplasty, 173 patient factors, 166–167 post-operative consideration, 174–175 restorative considerations, 173–174 site factors, 166 smile line, 167, 168 soft tissue management, 172–173 supra-crestal tissue attachment, 171 tooth proportions, 168–169 T Temporomandibular disorders (TMD), 61–62, 213 Temporomandibular joints (TMJs), 122 Tennis racket effect, 125 Tongue scalloping, 32 Tooth brushing technique, 190 Tooth wear, 16 control of aetiological factors, 288–290 dealing with failures, 285–288 energy drinks, 3 indices, 7–8 longevity, 284–285 management of patients, 8–9 monitoring, 10

Index pathological tooth wear, 4 prevention, 278–280 preventive management, 9–10 quality of life, 8 rationalise decisions, 11–12 recall appointment, 290–292 restorative intervention, 11, 281–284 types of abfraction, 7 abrasion, 6–7 attrition, 4 erosion, 4–5 Tooth wear evaluation system (TWES), 84 Tooth wear markers, 28–34 Treatment planning bis-acryl mock-up, 130 composite resin, 125 diagnostic wax-up, 130 extra-oral examination, 122 intra-oral examination, 123–125 occlusal vertical dimension, 126–128

309 orthodontic treatment, 125 patient history, 121–122 planning process, 128–130 post-orthodontic treatment, 125 restorative treatment anterior tooth wear management, 132 buccal composite restorations, 131 maxillary anterior teeth, 131, 132 maxillary incisors, 131 moderate anterior tooth wear, 132 static inter-cuspal holding contacts, 126 Turner classification, 126 Turner classification, 126 U UNC-15 periodontal probe, 170 X Xerostomia, 43–44