Successful Posterior Composites E-Book

Christopher D. Lynch

• Herausgeber: Quintessence Publishing Co. Ltd.
• Kategorie: Fachliteratur
• Serie: QuintEssentials of Dental Practice
• Sprache: Englisch

Seitenzahl: 186

Veröffentlichungsjahr: 2019

Beschreibung

The use of resin composite in posterior restorations is an accepted practice, offering a predictable and minimally invasive treatment. Resin composite can be regarded as the "material of choice" for restoring many posterior teeth that have been damaged by caries or trauma. This textbook reviews the most current concepts, presents techniques for successful results, and demonstrates how to avoid common pitfalls.

Leseprobe

Quintessentials of Dental Practice – 32Operative Dentistry – 6

Successful Posterior Composites

Author:

Christopher D Lynch

with contribution from Igor R Blum

Editors:

Nairn H F WilsonPaul A Brunton

Quintessence Publishing Co. Ltd.

London, Berlin, Chicago, Paris, Milan, Barcelona, Istanbul, São Paulo, Tokyo, New Delhi, Moscow, Prague, Warsaw

British Library Cataloguing in Publication Data

Lynch, Christopher D.Successful posterior composites. - (Quintessentials of dental practice; v. 32) 1. Dental resins 2. Fillings (Dentistry) I. Title II. Wilson, Nairn H. F. 617.6’95

ISBN: 1850973202

Copyright © 2008 Quintessence Publishing Co. Ltd., London

All rights reserved. This book or any part thereof may not be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, or otherwise, without the written permission of the publisher.

ISBN: 1-85097-320-2

Table of Contents

Title Page

Copyright Page

Foreword

Preface

Acknowledgements

Chapter 1 Posterior Composites: The State of Play

Aim

Outcome

Introduction

Are posterior composites effective?

Why is Composite Resin Better than Dental Amalgam?

The Way Forward

Key Learning Points

Further Reading

Chapter 2 Let’s Stick Together: How Do We “Bond” Composite Resin to Tooth?

Aim

Outcome

Ummm... Which Material Should I Use?

What is Composite Resin?

Newer Composite Materials

Making it Stick: Explaining Enamel and Dentine Bonding

Bonding to Enamel

Human enamel structure

How does enamel bonding work?

Bonding to Dentine

Human dentine structure

How does dentine bonding work?

Key Learning Points

Further Reading

Chapter 3 When Should We Place Posterior Composites?

Aim

Outcome

Introduction

Where and When

Patient-based Factors

Tooth-based Factors

Key Learning Points

Further Reading

Chapter 4 Getting Ready: Cavities for Posterior Composites

Aim

Outcome

Introduction

A Review of the Carious Process

Techniques for Diagnosing Dental Caries: Are We Really Sure It’s There?

Visual Examination

Transillumination

Radiographic Examination

Caries Detection Dyes

Electrical Conductance Methods

Fluorescence Methods

New Ways to Approach an Old Problem: Caries Management Strategies for Today

Risk Assessment

Mechanical Caries Removal

Chemomechanical Caries Removal

Other Approaches to Caries Management

Cavity Preparation: Promising Approaches

Cavity Isolation: No Substitute for Good Technique

How is rubber dam placed?

Cavity Design Features

Key Learning Points

Further Reading

Chapter 5 Protecting Dentine and Pulp: Do We Really Need a Base?

Aim

Outcome

Introduction

Management of Exposed Pulpal Tissues

To Base or not to Base ...

Sticking With What We Know: Bases

Glass–ionomer Systems

Resin-modified Glass–ionomers

New Approaches

Key Learning Points

Reference

Further Reading

Chapter 6 Shedding Light on Placement Techniques for Posterior Composites

Aim

Outcome

Introduction

Isolation

Placement

The Significance of the Filler:Resin Ratio

Polymerisation Contraction and Polymerisation Stress

The Polymerisation Mechanism

Curing Times

Delivering Light Activation

Quartz Tungsten–Halogen Units

Plasma Arc Lights

Light-emitting Diodes

General Notes on Composite Polymerisation and Placement

Finally, How Do We Do It?

Key Learning Points

Further Reading

Chapter 7 Getting Back in Touch: Restoring Proximal Contours

Aim

Outcome

Introduction

Problems

Selecting a Matrix System and Wedge Technique

Creating a “Good” Contact

So All This Means ...

Boxing Clever: Ensuring that the Margin of the Proximal Box is Sealed

Finally, How Do We Do It?

Key Learning Points

Further Reading

Chapter 8 Almost There: Finishing Techniques

Aim

Outcome

Introduction

How Should Posterior Composite Restorations be Finished?

The Occlusal Surface

Instrumentation

Water Cooling

Magnification

Finishing Tasks

Just When You Thought It Was All Over: Finishing Proximal Surfaces

Key Learning Points

Chapter 9 The Management of Failing Direct Composite Restorations: Replace or Repair?

Aim

Outcome

Introduction

Advantages of Repair

Criteria for Repair

Patient-centred Criteria

Tooth-specific Criteria

Clinical Indications for Restoration Repair

Secondary Caries

Marginal Defects and Marginal Staining

Superficial Colour Correction

Bulk Fracture

Fracture of Adjacent Tooth Tissue

Wear of the Restoration

Contraindications for Repair

Clinical Procedure

Repair of Fractured Tooth Tissue Adjacent to an Existing Amalgam Restoration

Clinical Procedure

Typical Bond Strength Values: How Well Will It Stick?

Conclusion

Key Learning Points

Recommended Reading

Chapter 10 Expanding Horizons: Advanced Uses of Posterior Composites

Aim

Outcome

Introduction

Managing Worn Posterior Teeth

Clinical Procedure

Cracked Tooth Syndrome

Restoring Endodontically Treated Teeth

Key Learning Points

Further Reading

Chapter 11 When Things Go Wrong: Trouble-shooting Posterior Composites

Aim

Outcome

Introduction

When the Worst Happens: What Can Go Wrong

Post-treatment Sensitivity

Playing the blame game

Restoration Fracture

Loss of Retention

Discoloration

Loss of Marginal Integrity

Food Packing

Loss of Pulpal Vitality

Key Learning Points

Chapter 12 Don’t Always Believe What You Read in Books: A Critique of Posterior Composites

Aim

Outcome

Concepts and Critical Issues

Foreword

The future of operative dentistry lies in prevention, risk assessment, minimally invasive techniques and the use of adhesively bonded, tooth-coloured restorative systems. An important aspect of the future of operative dentistry is the use of composite resins in the restoration of posterior teeth.

Composite resins for use in posterior teeth must never be thought of as a substitute for traditional materials; they are an alternative that offers a more modern, conservative approach to the restoration of damaged teeth, let alone being much more aesthetic than, in particular, dental amalgam. Furthermore, techniques for the use of composite resins suitable for the restoration of posterior teeth differ in important ways from the techniques for the successful use of composites in anterior teeth.

Successful Posterior Composites, one of the latest group of books to be published in the current highly acclaimed Quintessentials of Dental Practice series, provides students and practitioners of all levels of experience with a highly practical approach, based on best-available evidence, to the selection and application of composite resins in the restoration of posterior teeth.

Importantly, this book recognises that posterior composites are challenging, with consistent success requiring a good knowledge and understanding of the “where, when and how” of both the initial placement and post-treatment care of posterior composites in clinical service. All this and more is covered in this eminently readable, high-quality addition to the Quintessentials series.

Whatever your experience with posterior composites, this volume will expand and, it is hoped, reinforce elements of this important aspect of your clinical practice.

Mindful of the effective use of time required by busy practitioners and students, the author of this volume has gone to great lengths to produce a book that, in the spirit of the Quintessentials series, can be assimilated, with possible practice-changing effects, in a matter of a few hours – a great achievement in a subject area that is at the forefront of modern operative dentistry. For around the cost of one posterior composite, depending on size, type and complexity, this book is excellent value for money, let alone a great investment in keeping pace with the emerging future of operative dentistry.

Nairn Wilson Editor-in-Chief

Preface

Of the many advances in the practice of dentistry, perhaps the most revolutionary has been the development of predictable adhesive techniques. One of these techniques is the placement of composite resin as an alternative to dental amalgam in load-bearing cavities in premolar and molar teeth. As a consequence, minimally interventional dental techniques for the management of caries in posterior teeth are a reality; for example, there is no longer a requirement to remove excessive amounts of intact tooth tissue to provide retention for “non-adhesive” materials such as dental amalgam.

Confusion has arisen regarding the most suitable techniques to use when restoring posterior teeth with composite resin. This has been a reflection, in part, of the ever-increasing range of commercial products available for placing posterior composites, a lack of consensus and educational guidance on the suitability of many materials and techniques, and a varied experience of success (and failure!) by dental practitioners in the use of composite resin in posterior load-bearing cavities. Failures associated with posterior composites are often attributed to a lack of understanding of the nature of composite resins, coupled with inappropriate use, handling and placement techniques.

The aim of this book is to give clear guidance to general practitioners on how to approach the restoration of posterior load-bearing cavities with composite resin. This guidance is based on current best available evidence. Above all, this book is intended as a guide for busy general dental practitioners, who may be able to browse a section during a break in a busy day in clinical practice. The structure of this book will allow the busy practitioner to read individual chapters as “stand-alone” sections.

Posterior composites are now an established feature of contemporary restorative dentistry, and are “here to stay”. It is my sincere hope that all those reading this book will find it helpful and informative, and that they will come to enjoy placing successful posterior composites as much as I do.

Chris Lynch Cardiff

For Catherine

Acknowledgements

I would like to say “thank you” to the following people:

Professor Nairn Wilson for his continual encouragement and expert guidance during the preparation of this book.

My first teacher of adhesive dentistry, Professor Robert McConnell, for introducing me to the concepts of adhesive dentistry and posterior composite restorations, and who has taught me never to be afraid to embrace new ideas.

Professor Robin O’Sullivan, who has been my mentor and friend for many years … for teaching me that successful restorative and adhesive dentistry can only be truly understood in the context of oral biology, and in the structure and composition of the dental tissues with which we interact.

I am particularly indebted to Dr Igor Blum, Lecturer in Restorative Dentistry at the University of Bristol Dental School for writing Chapter 9; Dr Ali Kassir, Manchester University for Fig 2-3; Professor Robin O’Sullivan, Royal College of Surgeons – Medical University of Bahrain for Figs 2-8 and 5-1; Drs SB Jones and ME Barbour, University of Bristol Dental School for Fig 2-13; Dr Liam Jones for Fig 10-16. Sincere thanks to Mr Sam Evans and the staff of the Dental Illustration Unit at Cardiff University for their assistance in the production of many of the images in this textbook. Figures 4-7, 4-9, 4-10, 6-1, 9-2 and 9-3 are reproduced courtesy of Quintessence Publishing Co. Figure 10-6 is reproduced courtesy of Dental Update, and Figures 10-11b and 10-12 are reproduced courtesy of the Journal of the Canadian Dental Association. Thank you also to Ms Henriette Rintelen for producing the illustrations in this textbook, and Ms Mary O’Hara and the production staff at Quintessence UK for their expert support in producing the book.

Finally a big “thank you” to my friends – Dr Liam Jones, Professor Jeremy Rees, and Dr Alan Gilmour – for their suggestions, words of encouragement, and for reviewing this textbook prior to publication.

Chapter 1

Posterior Composites: The State of Play

NHF Wilson and CD Lynch

Aim

New knowledge and understanding, and the commercial development of composite resin materials and associated bonding technologies, mean that the placement of composite resin in occlusal and all but the largest occlusoproximal cavities may, given appropriate technique, be considered predictable and effective. The aim of this chapter is to describe state-of-the-art approaches to the placement of posterior composites.

Outcome

After reading this chapter, the reader will understand how new knowledge and understanding and developments in the field of composite resin materials and bonding technologies have resulted in the predictable and effective placement of load-bearing composite restorations in posterior cavities.

Introduction

Attitudes to the placement of posterior composites have undergone significant changes in recent years. As recently as the late 1990s, guidance on the placement of composite resins in posterior teeth restricted the application to “small occlusal and occlusoproximal cavities in premolar teeth, and preferably in those with limited occlusal function”. Educational surveys from that time demonstrated that most dental school graduates in Europe and North America had limited teaching in the placement of posterior composites, with many new dentists graduating with little or no clinical experience in their placement.

As a consequence of increased dental awareness in society, coupled with improvements in dietary and oral hygiene practices, many more patients, particularly younger patients, are now presenting with fewer and smaller lesions of caries than in the past (Figs 1-1 and 1-2). Such patients expect minimally interventive procedures, preferably using techniques that are described as “aesthetic” or “tooth coloured” (Fig 1-3). This, in association with commercial developments in composite resin materials and associated bonding technologies and lingering concerns over the safety of dental amalgam, has driven an increase in the placement of posterior composite restorations in general dental practice. For example, a survey of United Kingdom general dental practitioners in 2001 revealed, far from limiting the placement of composite to small cavities in premolar teeth, that almost one-half of general dental practitioners placed composite resin restorations in load-bearing cavities in molar teeth (Figs 1-4 to 1-6).

Fig 1-1 Mandibular dentition from a 30-year-old female, which is unrestored and caries free, albeit with some staining of occlusal fissures.

Fig 1-2 Bitewing radiograph from a healthy 35-year-old female demonstrating an absence of caries or restorations.

Fig 1-3 A recently placed composite restoration in the occlusal surface of a mandibular first molar.

Fig 1-4 A posterior composite restoration that has been in clinical service for over eight years.

Fig 1-5 The composite restorations in the maxillary premolars have been in clinical service for over 10 years. While there is some evidence of marginal staining, the restorations are serviceable. This is in contrast to the deteriorating dental amalgam restoration in the maxillary first molar.

Fig 1-6 An extensive posterior composite restoration in a root-filled maxillary first molar. This restoration has been in service for more than six years.

With ever increasing patient expectations, coupled with improvements in the physical properties of composite resin materials and bonding technologies, it is highly likely that the placement of composite resins in posterior teeth will continue to increase in clinical practice.

Are posterior composites effective?

The answer as to whether posterior composites are effective is a resounding “yes”. While some studies, dating back to the 1990s, found that the longevity of posterior composites was not as favourable as that of dental amalgam restorations, these studies investigated the use of composite resins as a substitute rather than an alternative to the use of dental amalgam. More recent studies indicate that the survival of posterior composite restorations can match, or even exceed, that of restorations of dental amalgam if they are applied to the best possible advantage. Indeed, dental insurance claims data in North America indicate that the longevity of posterior composites placed in general practice has matched and even surpassed that of dental amalgams. This has also been seen in recent studies of posterior restorations placed in general dental practice in Europe. Furthermore, as our understanding of the science of composite resins and bonding technologies increases, and practitioners become all the more familiar with the techniques necessary to place good-quality resin composite restorations, the survival rates of posterior composites will improve further.

One of the keys to success when placing posterior composites is to recognise that they are an alternative to, rather than a substitute for, dental amalgam and, as such, require very different operative techniques to those appropriate for dental amalgam. Dental amalgam is the “old workhorse” of operative dentistry. It is considered to be a forgiving, relatively easy material to place. In contrast, composite resins require meticulous attention to moisture control, must be placed using an incremental placement technique and are dependent on an array of equipment and devices including light-curing units, sophisticated matrix systems and multicomponent finishing processes, let alone the effective use of an appropriate dental adhesive. Notwithstanding these complexities, and the associated additional costs, the use of composite resins offers distinct advantages in clinical service over dental amalgams for the restoration of teeth damaged by caries and other insults.

Why is Composite Resin Better than Dental Amalgam?

Some of the advantages of appropriately applied composite resins over dental amalgams include:

a reduced need to remove sound tooth substance in preparation

opportunity to retain the restoration in non-retentive preparations through adhesive bonding to the remaining tooth tissues

an aesthetic tooth-coloured appearance (Fig 1-7)

reinforcement of the remaining tooth structure

increased fracture resistance of the restored tooth unit (Fig 1-8)

opportunity to repair and refurbish restorations in clinical service, thereby reducing the need for the total replacement of failing restorations (Fig 1-9).

Fig 1-7 While these dental amalgam restorations are clinically acceptable, they lack the aesthetics increasingly expected by patients.

Fig 1-8 Fractured tooth tissue adjacent to an extensive dental amalgam restoration in a mandibular first molar.

Fig 1-9 A repaired posterior composite restoration in a mandibular first molar; fracture of the distolingual cusp had occurred, and the area repaired with resin composite. A lighter shade of composite was selected to permit discrimination of underlying tooth tissue should further operative intervention be required.

Countering these advantages, there is evidence that posterior composites may be more susceptible to secondary caries than dental amalgams in cariogenic environments. Additionally, as and when total restoration replacement is indicated, dental amalgam, unlike most posterior composites, may be readily distinguished from remaining tooth tissue, thus limiting the risk of inadvertent removal of sound tooth tissue. As will be discussed later in this book, there are ways and means to minimise the effects of these limitations.

The Way Forward

For many practitioners, there is a growing ethical problem. Is it in the patient’s best interests to sacrifice sound tooth tissue to enable the effective application of dental amalgam, the tried and tested approach of 20th century operative dentistry, when it is possible to adopt minimally interventive preparation techniques through the use of a tooth-coloured alternative? It is suggested, as is now taught in many dental schools, that an adhesively bonded composite resin should be used to restore all but the largest initial lesion of caries, with particular techniques used if the preparation extends beyond the enamel cap, let alone subgingivally. Where dental amalgam has previously been used and the preparation may compromise the performance of a resin composite, as is often the case in the heavily restored dentitions of, for example, older patients, the reuse of dental amalgam may be the most efficient and effective restorative material. It should be remembered, however, that, once a preparation becomes complex and involves a number of surfaces of the tooth, an indirect cuspal coverage restoration will, in all probability, best enable the tooth to resist catastrophic failure under occlusal loading.

Given the above, it is apparent that a crossroads has been reached and passed in operative dentistry and the future will see continuing decline in the use of dental amalgam, albeit in some countries more quickly than others. Clinicians will need to move forward individually and collectively to work on continuing development in the application of resin composites and other tooth-coloured restorative systems. The goal is a style of operative dentistry that is less interventional and more aligned to the principle of the restoration of form, function and biomechanical performance of teeth than was possible with the approaches that dominated most of the 20th century.

Key Learning Points

Placement of posterior composites in occlusal and occlusoproximal load-bearing cavities is now a successful and predictable form of operative treatment. Selecting composite resin for placement in posterior cavities rather than dental amalgam effectively increases the lifespan of the restored tooth.

Composite resin is not “tooth-coloured dental amalgam”; it is an alternative to dental amalgam and as such it should not be handled or placed in the same way.

Dentists should consider composite resin as the “material of choice” for the restoration of most initial posterior cavities, and should only consider placing dental amalgam in the continuing care of heavily restored dentitions, in particular in older patients.

Further Reading

Lynch CD, McConnell RJ, Wilson NHF. Trends in the placement of posterior composites in dental schools. J Dent Educ 2007;71:430–434.

Manhart J, Chen HY, Hamm G, Hickel R. Review of the clinical survival of direct and indirect restorations in posterior teeth in the permanent dentition. Oper Dent 2004;29:481–508.

Opdam NJM, Bronkhurst EM, Roeters JM, Loomans BAC. A retrospective clinical study on longevity of posterior composite and amalgam restorations. Dent Mater 2007;23:2–8.

Chapter 2

Let’s Stick Together: How Do We “Bond” Composite Resin to Tooth?

Aim

Commercial and scientific developments have resulted in dental practitioners being presented with an ever-increasing array of composite resin materials and associated bonding technologies. The aim of this chapter is to review the means by which composite resins are bonded to tooth tissues.

Outcome

Having read this chapter, the reader will have:

an appreciation of the range of composite resin materials available for restoring posterior load-bearing cavities

an understanding of the significant properties and characteristics that should be considered when selecting an appropriate composite resin for restoring posterior load-bearing cavities

an understanding of the processes of enamel and dentine bonding.

Ummm... Which Material Should I Use?

One of the keys to the successful use of composite resins is recognition of the limitations of the selected material. The challenge for the busy dental practitioner is to select the most appropriate material, bearing in mind that inappropriate material selection can lead to early failure. The purpose of the following section is to provide some helpful advice in overcoming this problem.

What is Composite Resin?

Composite resin is a combination of a resin and filler particles that are united together using a coupling agent.

Composite resins were traditionally classified according to the size of the filler particles they contained (Fig 2-1). This classification included terms such as:

macrofilled composites, which include filler particles that vary in size from 1 to 15 μm and have a filler content in excess of 60% by volume

microfilled composites, which include filler particles that vary in size from 0.1 to 1 μm, and have a filler content varying between 20 and 50% by volume

hybrid composites, which include filler particles that contain a combination of microfiller and macrofiller particles up to 5 μm in size, and have a filler content varying between 50 and 70% by volume.

Fig 2-1 Differences in composition and filler sizes between macrofilled, microfilled and hybrid composite resins.

The properties of a composite vary according to the amount and size of the filler particles it contains:

Macrofilled composites