Fundamentals of Fixed Prosthodontics. James C. Kessler
detail.
As in all fields of the healing arts, there has been tremendous change in this area of dentistry in recent years. Improved materials, instruments, and techniques have made it possible for today’s operator with average skills to provide a service whose quality is on a par with that provided only by the most gifted dentist of years gone by. This is possible, however, only if the dentist has a thorough background in the principles of restorative dentistry and an intimate knowledge of the techniques required.
This book was designed to serve as an introduction to the area of restorative dentistry dealing with fixed partial dentures and cast metal, metal-ceramic, and all-ceramic restorations. It should provide the background knowledge needed by the novice as well as serve as a refresher for the practitioner or graduate student.
To provide the needed background for formulating rational judgments in the clinical environment, there are chapters dealing with the fundamentals of treatment planning, occlusion, and tooth preparation. In addition, sections of other chapters are devoted to the fundamentals of the respective subjects. Specific techniques and instruments are discussed because dentists and dental technicians must deal with them in their daily work.
Alternative techniques are given when there are multiple techniques widely used in the profession. Frequently, however, only one technique is presented. Cognizance is given to the fact that there is usually more than one acceptable way of accomplishing a particular task. However, in the limited time available in the undergraduate dental curriculum, there is usually time for the mastery of only one basic technique for accomplishing each of the various types of treatment.
An attempt has been made to provide a sound working background in the various facets of fixed prosthodontic therapy. Current information has been added to cover the increased use of new cements, new packaging and dispensing equipment for the use of impression materials, and changes in the management of soft tissues for impression making. New articulators, facebows, and concepts of occlusion needed attention, along with precise ways of making removable dies. The usage of periodontally weakened teeth requires different designs for preparations of teeth with exposed root morphology or molars that have lost a root.
Different ways of handling edentulous ridges with defects have given the dentist better control of the functional and cosmetic outcome. No longer are metal or ceramics needed to somehow mask the loss of bone and soft tissue. The biggest change in the replacement of missing teeth, of course, is the widespread use of endosseous implants, which make it possible to replace teeth without damaging adjacent sound teeth.
The increased emphasis on cosmetic restorations has necessitated expanding the chapters on those types of restorations. The design of resin-bonded fixed partial dentures has been moved to the chapters on partial coverage restorations. There are some uses for that type of restoration, but the indications are far more limited than they were thought to be a few years ago.
Updated references document the rationale for using materials and techniques and familiarize the reader with the literature in the various aspects of fixed prosthodontics. If more background information on specific topics is desired, several books are recommended: For detailed treatment of dental materials, refer to Kenneth J. Anusavice’s Phillip’s Science of Dental Materials, Eleventh Edition (Saunders, 2003) or William J. O’Brien’s Dental Materials and Their Selection, Fourth Edition (Quintessence, 2008). For an in-depth study of occlusion, see Jeffrey P. Okeson’s Management of Temporomandibular Disorders and Occlusion, Sixth Edition (Mosby, 2007). The topic of tooth preparations is discussed in detail in Fundamentals of Tooth Preparations (Quintessence, 1987) by Herbert T. Shillingburg et al. For detailed coverage of occlusal morphology used in waxing restorations, consult the Guide to Occlusal Waxing (Quintessence, 1984) by Herbert T. Shillingburg et al. Books of particular interest in the area of ceramics include W. Patrick Naylor’s Introduction to Metal Ceramic Technology (Quintessence, 2009) and Christoph Hämmerle et al’s Dental Ceramics: Essential Aspects for Clinical Practice (Quintessence, 2009).
—Herbert T. Shillingburg, Jr, DDS
Acknowledgments
No book is the work of just its authors. It is difficult to say which ideas are our own and which are an amalgam of those with whom we have associated. Two fine restorative dentists had an important influence on this book: Dr Robert Dewhirst and Dr Donald Fisher have been mentors, colleagues, and, most importantly, friends. Their philosophies have been our guide for the last 40 years. Dr Manville G. Duncanson, Jr, Professor Emeritus of Dental Materials, and Dr Dean Johnson, Professor Emeritus of Removable Prosthodontics, both of the University of Oklahoma, were forthcoming through the years with their suggestions, criticism, and shared knowledge. Thanks are also due to Mr James Robinson of Whip- Mix Corporation for his help with materials and instruments in the chapters that deal with laboratory procedures. Appreciation is expressed to Dr Mike Fling for his input regarding tooth preparations for laminate veneers. Thank you to Mr Lee Holmstead, Brasseler USA, for his assistance with the illustrations of the diamonds and carbide burs.
Illustrations have been done by several people through the years: Mr Robert Shackelford, Ms Laurel Kallenberger, Ms Jane Cripps, and Ms Judy Amico of the Graphics and Media Department of the University of Oklahoma Health Sciences Center. Artwork was also contributed by Drs Richard Jacobi and Herbert T. Shillingburg. This book would not have come to fruition without the illustrations provided by Ms Suzan Stone and the computer program, Topaz Simplify, suggested by Mr Alvin Flier, a friend from 40 years ago in Simi, California. A special thank you to the Rev John W. Price of Houston, Texas, for restoring my sense of mission in June 2008.
Thanks to you all.
1 An Introduction to Fixed Prosthodontics
The scope of fixed prosthodontics treatment can range from the restoration of a single tooth to the rehabilitation of the entire occlusion. Single teeth can be restored to full function, and improvement in esthetics can be achieved. Missing teeth can be replaced with fixed prostheses that will improve patient comfort and masticatory ability, maintain the health and integrity of the dental arches, and, in many instances, elevate the patient’s self-image.
It is also possible, through the use of fixed restorations, to render an optimal occlusion that improves the orthopedic stability of the temporomandibular joints (TMJs). On the other hand, with improper treatment of the occlusion, it is possible to create disharmony and damage to the stomatognathic system.
Terminology
A crown is a cemented or permanently affixed extracoronal restoration that covers, or veneers, the outer surface of the clinical crown. It should reproduce the morphology and contours of the damaged coronal portions of a tooth while performing its function. It should also protect the remaining tooth structure from further damage.
If it covers the entire clinical crown, the restoration is called a full veneer, full coverage, complete, or just a full crown (Fig 1-1). It may be fabricated entirely of a gold alloy or another untarnishable metal, a ceramic veneer fused to metal, an all-ceramic material, resin and metal, or resin only. If only portions of the clinical crown are veneered, the restoration is called a partial coverage or partial veneer crown (Fig 1-2).
Intracoronal restorations are those that fit within the anatomical contours of the clinical crown of a tooth. Inlays may be used as single-tooth restorations for Class II proximo-occlusal or Class V gingival lesions with minimal to moderate extensions. They may be made of gold alloy (Fig 1-3a), a ceramic material (Fig 1-3b), or processed resin. When modified with occlusal coverage, the intracoronal restoration is called an onlay and is useful for restoring more extensively damaged posterior teeth needing wide mesio-occlusodistal (MOD) restorations (Fig