McCabe John F. - Applied Dental Materials

2008 by Blackwell Publishing Ltd

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First published 1956. Second edition 1961. Third edition 1967. Fourth edition 1972.

Fifth edition 1976. Sixth edition 1985. Seventh edition 1990. Eighth edition 1998.

Ninth edition published 2008 by Blackwell Publishing Ltd

ISBN-13: 978-1-4051-3961-8

Library of Congress Cataloging-in-Publication Data

McCabe, J.F. (John F.)

Applied dental materials. 9th ed. / J.F. McCabe, A.W.G. Walls.

p. ; cm.

Includes bibliographical references and index.

ISBN: 978-1-4051-3961-8 (pbk. : alk. paper)

1. Dental materials. I. Walls, Angus. II. Title.

[DNLM: 1. Dental Materials. WU 190 M477a 2008]

RK652.5.A55 2008

617.695dc22

2007044377

A catalogue record for this title is available from the British Library

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Preface

In producing this ninth edition of Applied Dental Materials we have updated the text in both content and appearance. We hope that the book will remain helpful to students and teachers of the science of dental materials alike by remaining true to the core principles and developing them into a more comprehensive text which covers a wide spectrum of materials falling within the scope of dental materials. Hence, there are more references to practical issues like handling and clinical performance of materials, whilst maintaining a strong link to quality issues encompassed within newly developed ISO standards. Some areas, such as adhesion, ceramics, light activation technology, CAD-CAM have been developed and expanded significantly from the eighth edition, reflecting significant changes or developments in these areas. There is a new chapter on endodontic materials. All areas have benefited from a fresh approach to the use of drawings and photographs including the use of colour for the first time.

John McCabe

Angus Walls

The science of dental materials involves a study of the composition and properties of materials and the way in which they interact with the environment in which they are placed. The selection of materials for any given application can thus be undertaken with confidence and sound judgement.

The dentist spends much of his professional career handling materials and the success or failure of many forms of treatment depends upon the correct selection of materials possessing adequate properties, combined with careful manipulation.

It is no exaggeration to state that the dentist and dental technician have a wider variety of materials at their disposal than any other profession. Rigid polymers, elastomers, metals, alloys, ceramics, inorganic salts and composite materials are all commonly encountered. Some examples are given in along with some of their uses in dentistry.

This classification of materials embodies an enormous variation in material properties from hard, rigid materials at one extreme to soft, flexible products at the other.

Many dental materials are fixed permanently into the patients mouth or are removed only intermittently for cleaning. Such materials have to withstand the effects of a most hazardous environment. Temperature variations, wide variations in acidity or alkalinity and high stresses all have an effect on the durability of materials.

Normal temperature variations in the oral cavity lie between 32C and 37C depending on whether the mouth is open or closed. The ingestion of hot or cold food or drink however, extends this temperature range from 0C up to 70C. The acidity or alkalinity of fluids in the oral cavity as measured by pH varies from around pH 4 to pH 8.5, whilst the intake of acid fruit juices or alkaline medicaments can extend this range from pH 2 to pH 11.

The load on 1 mm2 of tooth or restorative material can reach levels as high as many kilograms indicating the demanding mechanical property requirements of some materials.

Many products, for example direct filling materials, are handled entirely by the dentist and their chairside assistant and are rarely encountered by the dental technician. Other materials are generally associated with the work of the dental laboratory and in this case both technician and dentist require a thorough knowledge of the materials in order that they may communicate about selection, manipulation and any problems which arise. A third group of materials link the dental surgery and the laboratory. The most obvious example of such products is the impression materials. Whilst the latter are under the direct control of the dentist it is essential that the dental technician also has a sound knowledge of such materials.

The process of materials selection should ideally follow a logical sequence involving (1) analysis of the problem, (2) consideration of requirements, (3) consideration of available materials and their properties, leading to (4) choice of material. Evaluation of the success or failure of a material may be used to influence future decisions on materials selection. This selection process is illustrated in . Many experienced practitioners carry out this sequence with no apparent effort since they are able to call upon a wealth of clinical experience. However, when presented with new or modified materials even the most experienced dentist should return to a more formal type of selection process based on the criteria mentioned.

Diagram indicating the wide variety of materials used in dentistry and some of their applications.