Planning and Making Crowns and Planning and Making Smith Bridges Howe Crowns and Fourth Edition This highly successful text, which has achieved wide acclaim among practitioners and is a Crowns and Bridges recommended text in the major dental schools, has again been revised and updated to keep it at the forefront of clinical practice. As before, the intention is to help solve real clinical problems by guiding dentists to make the right initial decision and then carry it through. Bridges This new edition includes significantly expanded material on veneers and implants in particular, so as to help dentists advise patients in their choice of what to do and how to make informed choices. FROM REVIEWS OF PREVIOUS EDITIONS: Fourth Edition 'well thought out and exceedingly well presented. I can wholeheartedly recommend this work as a worthwhile addition to any practitioner's bookshelf.' British Dental Review 'the greatest strength of the book lies in the sensible and comprehensive way it provides descriptions of clinical procedures' British Dental Journal Planning and Making 'must be considered a "best buy" for every practitioner interested in a planned approach to crown and bridgework' Dental Update ‘should be on every dentist’s bookshelf’ Dental Practice WITH OVER 600 COLOUR AND BLACK-AND-WHITE PHOTOGRAPHS CONTENTS: Indications and contraindications for crowns • Types of crown • Designing crown preparations • Occlusal considerations • Planning and making crowns • Clinical techniques for making crowns • Indications for bridges compared with partial dentures and implant-retained prostheses • Types of bridge • Components of bridges: retainers, pontics and connectors • Designing and planning bridges • Clinical techniques for bridge construction • Dental implants • Fixed splints • Crown and bridge failures and repairs Bernard GN Smith, BDS, PhD, MSc, MRD, FDSRCSEng, FDSRCSEdin, studied at the Universities of London and Michigan and spent a number of years in general practice. He is Professor Emeritus of Conservative Dentistry at Guy’s, King’s and St Thomas’ Dental Institute, Guy’s Hospital, London, and has served as examiner at several universities in Bernard GN Smith the UK and other countries and at the Royal Colleges of Surgery of England, Glasgow and Edinburgh, as Honorary Consultant in restorative dentistry to the British Army and as past President of the British Society of Restorative Dentistry. He has contributed to a wide range of dental journals and is the former editor of Restorative Dentistry. He is Leslie C Howe the joint author of Pickard’s Manual of Operative Dentistry. Leslie C Howe, BDS, FDSRCSEng, is a Consultant in Restorative Dentistry at Guy’s and St Thomas’ NHS Hospitals Trust, Guy’s Hospital, London, and a Specialist in Restorative Dentistry and Prosthodontics, and is in specialist practice Fourth in London. He is also the joint author of Implants in Clinical Dentistry. Edition www.informahealthcare.com Planning and making crowns and bridges Planning and making crowns and bridges Fourth Edition Bernard G N Smith BDS, PhD, MSc, MRD, FDSRCSEng, FDSRCSEdin Professor Emeritus of Conservative Dentistry Guy’s, Kings and St Thomas’ Dental Institute, London Leslie C Howe BDS FDSRCSEng Consultant in Restorative Dentistry Guy’s and St Thomas’ NHS Hospitals Trust and Private Practitioner © 1986, 1990, 1998 Bernard GN Smith, 2007 Bernard GN Smith and Leslie C Howe Fourth edition published in the United Kingdom in 2007 by Informa Healthcare 4 Park Square Milton Park Abingdon, Oxon OX14 4RN, UK Informa Healthcare is a trading division of Informa UK Ltd. Registered Office: 37/41 Mortimer Street, London W1T 3JH. Registered in England and Wales number 1072954. Tel: +44 (0)20 7017 6000 Fax: +44 (0)20 7017 6336 E-mail: [email protected] Website: www.informahealthcare.com All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior permission of the publisher or in accordance with the provisions of the Copyright, Designs and Patents Act 1988 or under the terms of any licence permitting limited copying issued by the Copyright Licensing Agency, 90 Tottenham Court Road, London W1P 0LP. The Authors have asserted their rights under the Copyright, Designs and Patents Act 1988 to be identified as the Authors of this Work. A CIP record for this book is available from the British Library. Library of Congress Cataloging-in-Publication Data Data available on application ISBN-10: 0 415 39850 9 ISBN-13: 978 0 415 39850 3 Distributed in the United States and Canada by Thieme New York 333 Seventh Avenue New York, NY 10001, USA Distributed in the rest of the world by Thomson Publishing Services Cheriton House North Way Andover, Hampshire SP10 5BE, UK Composition by Scribe Design Ltd, Ashford, Kent, UK Printed and bound in Contents Preface vii Acknowledgements ix Part 1 Crowns 1 Indications and contraindications for crowns 3 2 Types of crown 29 3 Designing crown preparations 53 4 Occlusal considerations 77 5 Planning and making crowns 105 6 Clinical techniques for making crowns 123 Part 2 Bridges 7 Indications for bridges compared with partial dentures and implant-retained prostheses 177 8 Types of bridge 197 9 Components of bridges: retainers, pontics and connectors 211 10 Designing and planning bridges 225 11 Clinical techniques for bridge construction 241 Part 3 Implants, splints and maintenance 12 Dental implants 261 13 Fixed splints 287 14 Crown and bridge failures and repairs 297 Index 319 Preface The aim of this book is to answer at least as many Undergraduate and postgraduate students need of the questions beginning with ‘why’ as those also to take advantage of their own and others’ that begin with ‘how’. A textbook is not the ideal clinical experience and learn by thinking about medium for teaching practical, clinical or techni- their clinical problems and talking about them cal procedures. These are best learnt at the chair- with others. Making the right decision is as impor- side and in the laboratory. However, the mass of tant as executing the treatment well. material which must be learnt, usually in a There is no reference to ‘case selection’ or restricted timetable, in the clinic and laboratory ‘patient selection’ for the techniques described. means that there is often insufficient time to That is not the way things are in practice. There answer the questions, ‘Why am I doing this?’ or, it is necessary to select the appropriate technique ‘When should I not do this?’ or even, ‘What on for the patient in front of you rather than select earth can I do here?’. the patient for the technique. Things are different The book is meant for clinicians, both under- in dental schools. It often happens that in order graduate and postgraduate, and so although the to provide a balanced range of experience for emphasis is on treatment planning, crown and undergraduate students in a limited period of bridge design and the related theory, clinical time, patients are selected to go on to particular techniques are also described in some detail. waiting lists to provide a flow of ‘clinical material’ Laboratory technique is, though, almost com- for the students’ needs. This may be necessary pletely omitted, both to keep the book to but the attitudes it sometimes develops are manageable proportions and because most clini- unfortunate. The essential feature of any profes- cians no longer undertake this themselves. It is sion is that it attempts to solve the problems of nevertheless abundantly clear that a good stan- its clients before concerning itself with its own dard of laboratory work is as important as the welfare. other phases in the construction of crowns, Because this is the approach, clinical photo- bridges and implants. graphs or at least photographs of extracted teeth The process may be divided into three stages: or casts, are used to illustrate the text in prefer- ence to line drawings, except where a photograph Initial decision making and mouth preparation is impractical. Photographs are used even when Clinical procedures the work shown is not ‘perfect’. No apology is Technical procedures. made for this. In reality, although we should strive for perfection (if we know what perfection is in The purpose of this book is to help quite a lot a given case, and we often do not), we will with the first stage, rather less with the second frequently not achieve it. It is more realistic to (a book cannot replace clinical experience) and talk about levels of acceptability. This is not to hardly at all with the third. advocate unnecessary compromise, but to recog- The intention is to help solve real clinical nise that in many situations a compromise (from problems. The student sitting in a technique knowledge, not ignorance) is necessary. After all, laboratory faced with an arch of intact perfectly the ideal would be to prevent caries, trauma and formed natural or artificial teeth planning to congenital deformity so that crowns and bridges undertake ‘ideal’ crown preparations will find were not necessary in the first place. Once they little help here. It may be good initial teaching to are needed there is already a situation that is less cut ‘classic’ preparations, but this is only part of than perfect. the training towards solving the real problems of Some of the work photographed is the authors’, real patients in the real world. The opinions some is undergraduate and postgraduate student expressed in a textbook can only go a little way work with a greater or lesser amount of help by further towards solving these problems. teachers, some of the technical work is carried out viii Preface by the clinicians themselves but most by techni- the new Chapter 12 on implants.