Descrição: Fundamentals of fatigue, Stress life approach, strain life approach, Fracture mechanics, Variable amplitude loading, Multi axial fatigue
Fundamentals of fatigue, Stress life approach, strain life approach, Fracture mechanics, Variable amplitude loading, Multi axial fatigueDescripción completa
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ALL THINGS RN these are my projects, research, reviewers, study guides i used during my college years. hope this will guide/help you through your nursing life, research, assignment, or your…Full description
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this book is very useful not for the beginners but also for the advenced who want to learn more about instrumentation.
Libro sobre aeronáutica y astrodinámica, tanto en su faceta teórica como en sus aplicaciones
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this book is very useful not for the beginners but also for the advenced who want to learn more about instrumentation.Full description
Libro sobre aeronáutica y astrodinámica, tanto en su faceta teórica como en sus aplicacionesFull description
this book is very useful not for the beginners but also for the advenced who want to learn more about instrumentation.
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Contents www.alllsJam.net http://dentalbooks-drbassam.blogspot.com/ Problem
Introduction
9
Chapter 1
Biomechanical Principles of Preparations
13
Chapter 2
Finish Lines and the Periodontium
45
Chapter 3
Instrumentation
61
Chapter 4
Full Veneer Crowns
83
Chapter 5
Maxillary Posterior Three-Quarter Crowns
95
Chapter 6
Mandibular Posterior Three-Quarter Crowns
115
Chapter 7
An terior Three-Quarter Crowns
133
Chapter 8
Pin-Modified Three-Quarter Crowns
153
Chapter 9
Seven-Eighths Crowns
173
Chapter 10
Proximal Half-Crowns
189
Chapter 11
tnlays
205
Chapter 12
MOD Ontays
237
Chapter 13
Anterior Porcelain-Fused-Io-Metal Crowns
259
Chapter 14
Posterior Porcelain-Fused-Io-Melal Crowns
279
Chapter 15
All-Ceramic Crowns
295
Chapter 16
Preparation Modifications for Damaged Teeth
321
Chapter 17
Preparation Modifications for Special Situations
359
Author Index
377
Subject Index
385
7
Chapter 1
Biomechanical Princ iples of Preparations www.slllslsm.net Problem The design and preparation of a tooth for a cast metal or porcelain restoration are governed by five princi p les: 1. 2. 3. 4. 5.
Preservation of tooth st ructure Retention and resistance form Structural durability of the restoration Marginal integrity Prese rvation of the pe riodontium
At times it may be necessary to compromise one or more for the sake of another. For example, sound tooth structure may have to be sacrificed in order to produce a more retentive form, to create space for the bulk of restorative material necessary for structural durability or an esthetic veneer, and to allow the restoration to seat with closefitting margins. Sound judgment must be exercised in making these compromises , with the requirements of the individual situation taken into careful conside ration.
Preservation of tooth structure Excessive removal of tooth structu re can have many ill effects. If a tooth is overtapered or shortened too much, there will be an unnecessary sacrifice of retention and resistance. Thermal hypersensitivity, pulpal inflammation, and necrosis can result from approaching the pulp too closely. As a guide to how
much tooth structu re can be safely removed, or how deeply a preparation may extend, the average thicknesses of enamel and dentin for permanent maxillary teeth are given in Table 1-1. Those for mandibular teeth are shown in Table 1-2. One of the most common violations of this principle is seen in the indiscriminate use of full-coverage porcelain veneered crowns in situations where partial veneer coverage with an allmetal restoration could be used. It is true that fUll-coverage restorations have long been recognized by clinicians as offering superior retention and resistance . 1 This has been borne out in recent years by several studies. 2-4 Howeve r, the shift in emphasis from partial venee r to full veneer restorations is more probably related to the ease and convenience associated with the design. 5--7 The decision to use full coverage should be reached only after a partial veneer crown has been considered and found wanting because of inadequate retention or esthetics . 8-- 11 Preservation of tooth structure entails more than simply avoiding excessive destruction. II also requires designing the restoration so that it will reinforce and protect the remaining enamel and dentin even when this means sacrificing a small amount of additional tooth structure on the occlusal surface to protect underlying cusps.
13
"-
Table ,-,
Enamel and dentin thicknesses in maxillary teeth (mm)" Midcrown
Occlusal Material
Incisal
CEJ
M
F
D
L
M
F
D
L
0.9 3.4
0.7 1.6
1.0 1.4
0.7 1.6
0.7 1.0
2.2
2.5
2.3
3.1
0.9 3.3
0.8
1.0
0.6
0.7
1.2
1.1
1.2
0.9
1.8
2.2
1.7
2.4
1.1
0.7 1.8
0.8 2.0
0.8 2.2
0.7 2.0
2.0
2.7
2.2
2.9
1.2
1.3
1.3
1.4 2.2
2.6
2.2
2.7
2.0
2.2
1.9
2.3
2.5
2.8
2.6
2.8
2.6
2.9
2.6
3.0
F
Cent
L
Central incisor
Enamel Dentin
Lateral Incisor
Enamel Dentin Canine
Enamel Dentin
4.4 Cusp
Cusp
1 .5
Groove 1 .3
3.0
3. 1
3.3
Cusp
Groove
1.7
1.3
Cusp 1.7
3.3
3.2
3.4
MF
DF
Cent
ML
DL
Cusp 1.8
Cusp 1.9
Fossa 0,6
Cusp 1.9
Cusp 1.9
First premolar
Enamel Dentin Second premolar
Enamel Dentin
First molar
Enamel Dentin Second molar
Enamel Dentin
3.9
1.8
1.1
1.3
1.1
1.4
1.31.51 .41.6
4.0
Cusp
Cusp
2.0 3.8
1.9
Fossa 0.5
Cusp 2.1
Cusp 1.9
1.3
1.4
1.3
4.4
'Mod,toed from H T ShoIIingburg and C S Grace. ThIckness of enamel and denim. J Soutn. Calil Dent Assoc_. 41 33. 1973
1.6
Table 1-2
Enamel and dentin thicknesses in mandibular teeth (mm)" Occlusal
Material
Incisal
F
Cent
CEJ
Midcrown M
F
D
L
M
F
D
L
0.9 3.7
0.6
0.9
1.1
1.1
0.7 1.2
0.6 0.9
15
23
1.5
2.4
1.0 3.6
0.6 2.0
0.8 2.0
0.8 2.1
0.6 2.1
2.8
22
2.9
1.0
1.2
1.0
1.1
2.1
2.5
2.1
2.8
22
2.6
2.2
2.5
2.5
2.8
2.7
2.6
2.5
3.0
2.8
2.6
L
Incisor Enamel Dentin Canine Enamel
Dentin First premolar
Enamel Dentin
Second premolar Enamel Dentin
First molar
Enamel Dentin Second molar
Enamel Dentin
Cusp
Groove
Cusp
1.3 3.2
1.2 2.0
1.1
3.0
Cusp
Groove
Cusp
1.6 3.4
1.3 2.7
1.6 3.8
1.1
MF
DF
D
CENT
ML
DL
Cusp
Cusp 1.8
Cusp 1. 9
Fossa 0.5
Cusp
Cusp
1.9 3.7
1.8 3.3
2.0 3.8
3.3
Cusp
Cusp
Fossa
Cusp
Cusp
2.0 3.6
1.9 36
0.5
1.8
1.8 3.6
3.3
1.2
1.4
1.3
1.5
1.6
1.1
1.3
1.5
~
Ul
"MOd,had from H T Shillingburg and C S, Graco, Thickness 01 enamel and denlln. J South Cal"
