Protocols for Predictable Aesthetic Dental Restorations

229 Pages·2006·5.71 MB·English

by  Irfan Ahmad(auth.)

Protocols for
Predictable Aesthetic
Dental Restorations
Protocols for
Predictable Aesthetic
Dental Restorations
Irfan Ahmad
BDS, The Ridgeway Dental Surgery, Middlesex, UK
Active member European Academy of Esthetic Dentistry
© 2006 I. Ahmad
Blackwell Munksgaard, a Blackwell Publishing Company,
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First published 2006 by Blackwell Munksgaard
ISBN-13: 978-14051-1820-0
ISBN-10: 1-4051-1820-2
Library of Congress Cataloging-in-Publication Data
Ahmad, Irfan, BDS.
Protocols for predictable aesthetic dental restorations / Irfan Ahmad.
p. cm.
Includes bibliographical references and index.
ISBN-13: 978-1-4051-1820-0 (pbk. : alk. paper)
ISBN-10: 1-4051-1820-2 (pbk. : alk. paper)
1. Dentistry–Aesthetic aspects. 2. Prosthodontics. I. Title.
[DNLM: 1. Esthetics, Dental. 2. Dental Restoration, Permanent.
3. Dental Restoration, Temporary. WU 100 A286p 2006]
RK54.A46 2006
617.6′9–dc22
2005024528
A catalogue record for this title is available from the British Library
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Note:the author is an invited lecturer for many dental organisations but has no financial interests
and no formal links with any of these organisations.
Contents
Dedication viii Aesthetics 37
Foreword by Ronald E.Goldstein ix Facial composition 38
Preface xi Dentofacial composition 41
Dental composition 45
1 Treatment planning – assessment, Gingival composition 48
planning and treatment 1
Assessment 1
Planning 3 3 Choice of all-ceramic
Diagnosis 3 systems 55
Risk assessment 3
Scientific rationale 55
Evidence-based decision making
Rationale for all-ceramic
and treatment 6
restorations 55
Presenting treatment plan proposals
Physical and mechanical properties
to the patient 9
of ceramic 58
Treatment 11
Uni-layer and bi-layer all-ceramic
Clinical case study 12
systems 58
Assessment 12
Aetiology of fractures 59
Planning 13
Dental ceramics 60
Treatment 16
Silica-based ceramics 61
Alumina-based ceramics 65
2 The health, function and
Zirconia-based ceramics 68
aesthetic triad 21
Longevity 69
Health 21 Metal–ceramic 69
The periodontium 22 Dicor and Cerestore 70
Restorative implications 29 IPS-Empress 1 70
Implants 29 In-Ceram Alumina 70
Function 30 Procera 70
Occlusion 30 Ceramic bridges (FPDs) 70
Phonetics 36 Clinical practice 73
vi Contents
4 Colour and shade analysis 77 Criteria for intra-radicular post
selection 106
Scientific rationale 77
Coronal dentine and the ferrule
The stimulus for colour 78
effect 106
The illuminant 78
Tapered vs.parallel 106
The object 79
Smooth vs.serrated 107
Sensation (the detector) 81
Passive vs.active 107
Synopsis of the stimulus for
Direct vs.indirect technique 107
colour 83
Single- vs.multi-rooted teeth 109
Perception 83
Choice of luting agents 109
Tooth colour determination 85
Aesthetics 110
Physical variables 85
Types of cores 113
Physiological variables 86
Modes of failure 114
Psychological variables 86
Loss of retention 115
Dental variables 87
Post fractures 115
Other optical variables influencing
Root fractures 116
colour 89
Pre-post placement assessment 117
Shade guides 90
Endodontic factors 117
Types of shade guide 91
Periodontal factors 117
Limitations of shade guides 93
Choice of definitive
Instrumental assessment 93
restoration 118
Spectrophotometer 94
Remaining coronal dentine 118
Colorimeter 94
Tooth location 118
Digital camera and red,green,blue
Summary 118
(RGB) devices 94
Non-vital teeth – clinical practice 118
Clinical practice 94
Ocular shade assessment 95
Instrumental shade assessment 96
6 Tooth preparation 125
5 Foundations and
Scientific rationale 125
intra-radicular support 98
Reasons for extra-coronal
Introduction 98 restorations 125
Vital teeth – scientific rationale 98 Biologic width 127
Vital teeth 98 Margin location 128
Retention 99 Margin geometry 130
Vital teeth – clinical practice 102 Preparation design 131
Pre-assessment for cores on vital Maintenance of dental hard tissue
teeth 102 integrity 133
Radiographic evaluation 102 Cutting efficiency 135
Intra-oral evaluation 102 Clinical practice 135
Clinical sequalae for cores on vital Anterior tooth preparation 135
teeth 102 Assessment 136
Non-vital teeth – scientific rationale 103 Planning 136
Post materials 103 Treatment 137
Casting alloys 103 Posterior tooth preparation 140
Prefabricated metal 103 Assessment 140
Ceramics 104 Planning 140
Fibre 104 Treatment 141
Contents vii
7 Therapeutic temporary Impression materials 169
restorations 145 Primary determinant 172
Patient factors (risk assessment) 173
Introduction 145
Operator factors 174
Scientific rationale 145
Clinical practice 177
Health 145
Dental biological impressions 177
Function 147
Gingival biological impressions 179
Aesthetics 147
Biocompatibility 151
Strength 151
9 Try-in procedures 185
Palliative 151
Marginal integrity 152 Clinical practice 186
Preventing plaque accumulation 153 Extra-oral evaluation 186
Chromatic stability 155 Inspection of restoration on
Handling characteristics and ease of trimmed die 187
fabrication 155 Inspection of restoration on
Material selection 155 untrimmed die 188
Polymethyl methacrylate (PMMA) 156 Intra-oral evaluation 189
Polyvinyl ethylmethacrylate
(PVEMA) 156
Bis-GMA resin 157 10 Cementation and dentine
Bis-acryl resin composite 157 bonding agents 191
Urethane dimethacrylate (UDMA)
Scientific rationale 191
resin 157
Types and properties of luting
Clinical practice 157
agents 191
Fabrication 157
Zinc oxide eugenol (ZOE) 191
Matrices 158
Zinc phosphate (ZP) 192
Existing anatomical form 158
Polycarboxylate (PC) 192
Proposed anatomical form 158
Glass ionomer (GI) 192
Preformed metal and plastic
Resin-modified glass ionomer
crown forms 159
(RGI) 192
Techniques 159
Dual-polymerisation resins (DR) 192
Direct technique 160
Self-adhesive,dual-polymerisation
Indirect technique 162
resins (SADR) 192
Direct–indirect technique 162
Self adhesive,auto-polymerisation
resins (SAAR) 193
8 Biological impressions 165
Ceramic primers (CP) 193
Introduction 165 Efficacy of cementing agents 193
Scientific rationale 165 Adhesion 193
Secondary determinants 166 Occlusal stresses 194
Stock vs.custom trays 166 Marginal integrity and leakage 195
Inter- vs.intra-arch 166 Retention 196
Closed vs.open tray 167 Pre-treatment of abutment 197
One vs.two stages 167 Dentine bonding agents 197
Passive vs.non-passive 168 Efficacy 201
Warm vs.cold environment 168 Pre-treatment of intaglio surface 202
Manual vs.automated mixing 168 Clinical practice 203
Physical vs.chemical gingival
retraction 168 Index 211
Dedication
To my wife and soul companion, Samar, and my son Zayan.
Foreword
I have always thought that any teacher of beauty, tional and an esthetic result. Thus it is both
including cosmetic dentistry, should have an refreshing and a true learning experience to dis-
artistic “eye.” In my opinion, Irfan Ahmad falls cover Dr Ahmad’s unique way of how to accom-
within this requirement. The first time I saw him plish his esthetic goals.
lecture I was quite impressed with his under- It has been over thirty years since I wrote the
standing and attention to all that is classified first edition of Esthetics in Dentistry. This was
as esthetic. So, it is appropriate that Dr Ahmad the very first comprehensive textbook describing
has authored Protocolsfor Predictable Aesthetic esthetic techniques both as an entity as well as a
Dental Restorations. His approach to basic and vital part of interdisciplinary dentistry. Working
advanced principles of esthetics is well grounded. with specialists for virtually all disciplines of
Although each of us may have our own way of dentistry, this concept has now been finally
doing a particular procedure we should never- accepted into what we consider the prevailing
theless realize that there is more than one way to standard of care in both diagnosis and treatment
achieve the same goal and therefore Dr Ahmad’s planning.
unique approach to problems is well worth our Dr Ahmad understands this concept and thus
attention. His stunning photography is both cre- he spends most of his text dealing with the details
ative and educational, making step-by-step pro- of how he, and we, should be achieving greater
cedures easier to comprehend. All too often we success with all ceramic crowns and bridges. Just
see self-styled clinicians who both lecture and as I did in my first text, Dr Ahmad devotes a
write as if they originated every single technique chapter to each of the essential six steps to a suc-
they show and with little or no evidence to back cessful restoration. There is an important lesson
up their claims. Therefore it is refreshing to see in spending an entire chapter on each step, and
that Dr Ahmad relies on evidenced-based princi- that is not only to learn new tips on being more
ples to back up his artistic talent. The uniqueness efficient and seeing if another method is better
of our profession is that we are not all “clones,” than the one you currently use, but also that each
each of us has his or her own “tricks” or tech- of the steps is a separate entity. This helps us con-
nique to accomplish a common goal – that of stantly remember to spend an adequate amount
pleasing the patient and achieving both a func- of time with attention to detail, so that in the end
x Foreword
we will have done our very best in each phase of this difference and I am so pleased he chose to
the restoration. It is this attention to detail that share that “difference” with all of us.
can make the difference between an ordinary and
an extraordinary restoration. Dr Ahmad knows Roland E. Goldstein, DDS
Preface
The aim of this book is to furnish the clinician transport the reader through successive stages for
with knowledge for providing aesthetic dental providing aesthetic dental restorations. Most
restorations that are virtually indistinguishable chapters commence with scientific rationale and
from natural teeth. Dental aesthetics is intangi- finish with clinical practice, applying theory to a
ble, influenced by the wishes of the patient, ex- practical scenario. Whilst the learning curve at
perience of the clinician, and the artistic and times seems onerous, once mastered the tech-
technical skills of the ceramist. Aesthetics lies in niques can be expedited for making aesthetic
the murky twilight between art and science. Art restorations that are predictable, functional
is not enough to create aesthetic restorations, and long lasting. Furthermore, the systematic
while science alone is inadequate for pleasing approach adopted in this book gains patient
results. However, the clinical protocols necessary gratitude and creates clinical satisfaction.
for aesthetic restorations are tangible, relying on I am indebted to Ronald Goldstein, who is
biological concepts combined with scientific undoubtedly regarded as the pioneer of aesthetic
research. Using the health, function and aesthetic dentistry. The two people who have spurred me
(HFA) triad, the clinician and ceramist can on: Bernard Touati and Nitzan Bichacho, as well
deliver prostheses that are durable and har- as eminent clinicians who have helped, directly
monise with surrounding soft and hard tissues. or indirectly, with this project, including Avishai
The appearance of dental restorations is subjec- Sadan, Gerard Chiche, Markus Blatz, Tom
tive: one person’s Xanadu may be another’s Trinkner, William Liebenberg, Alan Gluskin,
Inferno. Aesthetics is a passion, not a craft, and Homa Zadeh, Fereidoun Daftary, Stefano
one that has to be sought rather than taught. Gracis, Mauro Fradeani, Douglas Terry, Stephen
According to Carl Jung, ‘A man who has not Hancocks, RafiRomano, Galip Gürel, Alan Sidi,
passed through the inferno of his passions has Eric van Doreen, Youval Elyat, Ervin Weiss,
never overcome them’. Nitzan Fuhrer, Ilan Gilboa, members of the
The layout of the book is a chronological European Academy of Esthetic Dentistry and
clinical journey, starting with treatment planning Dentology study group, especially Sanjay Sethi,
and ending with cementation. The intervening who founded Dentology five years ago for like-
chapters between these start and end points minded clinicians.