Implantology in General Dental Practice E-Book

Lloyd J. Searson

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

Seitenzahl: 102

Veröffentlichungsjahr: 2019

Beschreibung

Increased media attention and research have heightened awareness of dental implants as an option for missing teeth. The general practitioner is now expected to offer implants when discussing restorative treatment with patients. This book aims to explain current best practice in the principles of patient assessment and treatment planning, implant selection criteria, and surgical and restorative treatment protocols for achieving optimum functional and cosmetic results according to each individual patient's clinical needs and requirements.

Leseprobe

Quintessentials of Dental Practice – 4

Implantology in General Dental Practice

Authors:

Lloyd Searson

Martin Gough

Ken Hemmings

Editor:

Nairn H F Wilson

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

Searson, Lloyd J. J. Implantology in general dental practice. - (Quintessentials of dental practice; 4) 1. Dental implants I. Title II. Gough, Martin III. Hemmings, Kenneth W. 617.6 ′9

ISBN 1850973377

Copyright © 2005 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 1-85097-337-7

Table of Contents

Title Page

Copyright Page

Foreword

Preface

Acknowledgements

Chapter 1 History and Development of Dental Implants

Aim

Outcome

Introduction

Implants

Subperiosteal

Transosseous

Endosseous

Factors Influencing Implant Osseointegration

Implant Design

Implant Length

Implant Diameters

Surface Characteristics

The Host Site

Bone Factors

General Health

Age

Smoking

Radiotherapy

Surgical Technique

Surgical Experience

Operating Conditions

Incision Technique

Drilling Technique

Healing and Loading Times

Implant Componentry

Implant Design

Implant to Abutment Connection and Implant to Final Prostheses Connection

Screw-Retained Prostheses Connection

Cement-Retained Prostheses Connection

Abutment

Choice of Implants System

Conclusions

Further Reading

Chapter 2 Case Selection

Aim

Outcome

Introduction

Reasons for Tooth Loss

Periodontal Disease

Dental Caries

Endodontic Failure

Trauma

Hypodontia

Why Replace Missing Teeth?

Options for Replacing Teeth

Orthodontic Treatment

Removable Dentures

Resin-Bonded Bridgework

Conventional Bridges

Dental Implants

Conclusions

Further Reading

Chapter 3 Patient Assessment and Treatment-Planning

Aim

Outcome

Introduction

Clinical Assessment

Medical History

Smoking

Diabetes

Facial Pain

Psychological Problems

Dental History

Clinical Examination

Extraoral

Intraoral

Study Casts

Radiographic Examination

Axial Tomograms

Long-Cone Periapical Radiographs

CT Scans

Computer-Guided Technology (CAD-CAM)

Tomograms

Treatment-Planning

Controlling the Environment

Extraction of Teeth

Timing of Extractions

Delayed Placement

Immediate Placement of Implant into Extraction Site

The Number and the Position of Implants

Conclusions

Further Reading

Chapter 4 Surgery

Aim

Outcome

Introduction

Mandible

Inferior Dental Canal

Mental Foramina

Submandibular Fossa

Maxilla

Maxillary Antrum

Incisive Canal

Bone Quality

Surgical Technique

Implant Positioning

Guidelines for Implant Positioning

Preoperative Planning

Radiographs

Study Casts

Surgical Planning Software

Surgical Techniques

First Stage Surgery

Flap Design

Bone Preparation

Single or Two-Stage Surgery

Second-Stage Surgery

Immediate Placement

Immediate Loading

Conclusions

Further Reading

Chapter 5 Prosthodontic Procedures

Aim

Outcome

Introduction

Restoration of the Single Tooth Implant

Torque Wrench

Impression Procedure

Occlusal Registration

Shade Taking

Temporisation

Customised Abutments

Partial Replacement Case

Edentulous Case

Laboratory Considerations

CAD-CAM

Key Points

Further reading

Chapter 6 Advanced Cases

Aim

Outcome

Introduction

Full Mouth Reconstruction

Aesthetics

Temporary Superstructure

Impression Procedures

Dental Implants and Periodontal Disease

Immediate Implant Placement

Tissue Augmentation

Bone Graft

Soft-Tissue Grafting

Guided Tissue Regeneration (GTR)

Immediate Loading

Maxillofacial Prosthodontics

Conclusions

Reference

Further Reading

Chapter 7 Complications and Maintenance

Aim

Outcome

Introduction

Surgical Complications

Postoperative Pain

Wound Dehiscence

Paraesthesia

Mandibular Fractures

Complications Following Second-Stage Surgery

Failure to Integrate

Excessive Bone over the Cover Screw

Bone Growth between the Cover Screw and Implant

Prosthetic Complications

Biomechanical Problems

Fracture of the Prosthesis

Loosening or Fracturing of Screws

Lute Failure in a Cement-Retained Prosthesis

Fracture or Loss of the Implant

Physiological Problems

Maintenance

The Prosthesis

The Soft Tissues

Conclusions

Further Reading

Chapter 8 The Future

Aim

Outcome

Introduction

Paediatric Dentistry

Orthodontics

Restorative Dentistry

Periodontics

Endodontics

Maxillofacial Surgery and Prosthodontics

Education

Research

Challenges

Conclusions

Foreword

Implantology is one of the most exciting and dynamic aspects of modern dentistry. Developments in implant systems and techniques have transformed prosthodontics at all levels. Practitioners not yet into implants, and those whose knowledge and understanding in this field are limited, will find this addition to the Quintessentials of Dental Practice series to be an excellent acquisition. Apart from dispelling much of the mystique that has built up around implants and their use, this book provides an abundance of practical guidance of immediate relevance to everyday clinical practice. As with all the volumes in the Quintessential series, this book is not intended to be a comprehensive tome on the subject; it is a succinct, easy-to-read, well illustrated overview of key points and essential guidance.

Whether this book is your starting point, springboard to more comprehensive texts or aid to reinforce existing knowledge and understanding of implantology, it should not disappoint. Indeed, I would be dismayed if it did not stimulate its readers to offer at least some, or hopefully more, implant-based forms of treatment to their patients. Do you owe it to your patients, professional development and practice to purchase this volume and find the few hours needed to read it from cover to cover? If you do, it will be time and money well spent.

Nairn Wilson Editor-in-Chief

Preface

Implants are now a recognised treatment for partially dentate and edentulous patients. This book is based on our joint experiences over 15 years working in the Restorative Department at the Eastman Dental Hospital and in private practice. Our aim is to provide general dental practitioners with a concise introduction to dental implantology and enable them to discuss implants as a treatment option with patients.

Lloyd Searson Martin Gough Ken Hemmings

Acknowledgements

We would like to thank the many people who have helped us put together all the information included. Particularly we would like to thank Dr David Gallacher, Radiology department, Guy’s and St Thomas’ Hospital, and Dr Anthony Reynolds, Image Diagnostic Technology Ltd, The London Imaging Centre. Our special thanks go to all the highly skilled technical teams at the Eastman Dental Hospital.

Chapter 1

History and Development of Dental Implants

Aim

The aim of this chapter is to familiarise the reader with the history and development of dental implants and with relevant terminology and implant characteristics.

Outcome

After reading this chapter the reader should have an understanding of dental implants, their design and characteristics and the various components that are used in implant dentistry.

Introduction

Tooth loss as a result of disease, trauma, failure to develop and the adverse consequence of partial dentures is common. It is not surprising, therefore, that the history of tooth replacement has been long and multifaceted. Depending on the degree of edentulism, several treatment options are available, including:

no replacement

removable partial dentures

complete dentures

conventional or adhesive bridgework

implant-supported prostheses

transplantation.

The management of edentulism poses a challenge to the practitioner. Evidence from ancient civilisations has shown throughout history that man has tried to replace missing and lost teeth with various materials, including carved ivory, wood and bone. At times, natural teeth were extracted from paupers and casualties of war to replace missing teeth in the wealthy.

It was not until the 19th century that experiments using different materials and designs of appliances to replace missing teeth were reported in the dental literature. Attempted replacements ranged from the use of root-form gold implants placed into sockets to iridium-platinum basket-type endosteal implants with screws.

Before the 1950s implant placement was more of an art form than a science. It was not until the late 1970s/early 1980s that the use of dental implants became more scientific and implantology was recognised by the academic community.

The two main research groups responsible for the underpinning science were Brånemark and co-workers in the late 1960s, and Schroeder and co-workers in the mid-1970s. Both research groups established that direct contact exists between bone and dental titanium implants and that this contact results in the clinical stability of an implant during loading. For this mode of anchorage, Brånemark and co-workers coined the term “osseointegration” in 1967. Osseointegration is the direct structural and functional connection between ordered living bone and the surface of a load-carrying implant.

Osseointegration heralded a fundamental scientific shift in thinking, previous implants having tended to develop a fibrous attachment that, it was hoped, could serve the same purpose as the periodontal ligament. The periodontal ligament is a specialised structure that serves as an effective attachment mechanism, a shock absorber and a sensory organ. Furthermore, the periodontal ligament is capable of mediating bone remodelling, allowing tooth movement. Previous non-integrating forms of implants may have been anchored to bone by means of a surrounding sheath of pseudo periodontal ligament, but this fibrous sheath was a poorly differentiated layer of scar tissue. In most cases, loading and gradual widening of this led to loosening of the implant and subsequent implant failure (Fig 1-1).

Fig 1-1 Radiograph of blade implant showing implant failure.

Implants

There are three types of implants available:

subperiosteal

transosseous

endosseous.

Subperiosteal

This type of implant consists of a non-osteointegrated framework that rests on the surface bone of the mandible or maxilla. The framework is positioned beneath the mucosa with, typically, a number of posts penetrating the mucosa to support an overdenture.

Subperiosteal implants were originally introduced in the 1940s and served patients well for many years. Unfortunately, problems experienced included infection, exteriorisation by the downgrowth of epithelium and damage to the underlying bone. In some cases the subperiosteal implant would submerge into the bone, making it extremely difficult to remove (Fig 1-2).

Fig 1-2 (a) Subperiosteal implant and (b) radiograph showing extensive bone loss around a subperiosteal implant.

Transosseous

The transmandibular staple is the most used form of transosseous implant, consisting of a gold plate fitted to the lower border of the mandible and posts placed directly through the mandible to provide support for some form of denture. This approach was suitable only for the mandible. Although some reports show good results over periods of up to 10 years, the use of transosseous implants has been largely discontinued (Fig 1-3 and Fig 1-4).

Fig 1-3 Transosseous implant frame.

Fig 1-4 Intraoral view of transmandibular staple implant.

Endosseous

These implants can be placed in the maxilla or mandible through an intraoral incision in the mucoperiosteum. The shapes and construction of endosseous implants have varied over the years, but the past two decades have seen the most dynamic developments. The clinician may be bewildered by the variety of implant shapes and designs available. However, various groups have developed certain criteria that aid the selection of implant systems. For example, Albrektsson and co-workers (1986) proposed the following criteria for a successful implant:

The freestanding implant should be rigid clinically.

Radiographic examination does not reveal any peri-implant radiolucency.

In clinical service radiographic vertical bone loss is less than 0.2mm each year.

Absence of signs or symptoms of failure, including pain, infection, neuropathies, paraesthesia or violation of anatomical structures.

A success rate of 85% at the end of a five-year observation period and 80% at the end of a 10-year period.

Factors Influencing Implant Osseointegration

Osseointegration is a union between bone and the implant surface. It can be measured histologically as the proportion of the total implant surface that is in direct contact with bone. Different levels of bone contact may occur with implants of different materials. There are a number of factors that may influence the degree of osseointegration, relating to one of three parameters:

implant design

host site

surgical technique.

Implant Design

Most contemporary dental implants are made of commercially pure titanium, which has been shown to have excellent biocompatibility. Titanium is a light metal. When exposed to air, a surface oxide is rapidly formed. This layer of oxide determines the biological response. Commercially pure titanium is also highly resistant to corrosion. Other metals have been used for osseointegration, including zirconium, gold and titanium-aluminium-vanadium alloys. These alloys may strengthen the implant but have been shown to have relatively poor bone-to-implant contact.

Implant design has a great influence on the stability and subsequent function of the implant in bone. The main parameters are implant shape, implant length, implant diameter and surface characteristics. Root-form implants, such as screws and cylinders, are the dominating implant designs today. Screw implants are considered to be superior to cylindrical ones in terms of initial stability and resistance to compression and tension stresses under loading (Fig 1-5).

Fig 1-5 Screw-shaped implant with abutment and final prosthesis in position.

Implant Length

Research findings have shown that shorter implants fail more often than longer implants. Implant length varies from 6–20mm. The most common lengths employed are between 8–15mm. It is good practice to use the longest implant that can be safely placed, with, wherever possible bicortical stability. Clearly, certain anatomical limitations exist, for example, in the posterior mandible behind the mental foramen.

Implant Diameters

The diameter of most implants falls within the range of 3.3–6mm. Narrow diameter implants can be used in small spaces. Larger diameter implants may be used, in particular in posterior areas of the mouth and where there is poor quality bone.

Surface Characteristics