5. All-Ceramic crowns Flashcards
(164 cards)
1
Q
Define all ceramic crown
A
Ceramic FPD without supporting metal framework
2
Q
Land’s classical jacket crown? (3)
A
- Obsolete
- feldespathic porcelain fused over platnium foil
3
Q
Mclean and hughes’ classical jacket crown? (5)
A
- Obsolete
- Aluminous porcelain coping (40% Al2O3).
- Feldspathic veneering porcelain.
- Opaque coping.
- Low fracture toughness
4
Q
Mclean’s classical jacket crown?
A
- obsolete
- Aluminous porcelain with platinum foil coping
- is a variant of MClean and hughes’
- tougher
- less esthetic
5
Q
Why is mclean’s classical jacket crown less esthetic?
A
Decreased light transmission
6
Q
What is the defining characteristic of current jacket crowns?
A
Reinforced to provide improved toughness and/or esthetics
7
Q
Material characteristics of dental ceramics? (4)
A
- Inert
- Metallic oxides
- no liberation of ions into the mouth
- Highly biocompatible
8
Q
What are the different phases of dental ceramics? (2)
A
- Vitreous
- Crystalline
9
Q
What are dental ceramics made of? (2)
A
Vitreous matrix and mineral crystals
10
Q
What provides the different properties of ceramics?
A
The percentage of vitreous matrix vs mineral crystals
11
Q
How is the marginal fit of dental ceramics?
A
Good
12
Q
What are the mechanical properties of dental ceramics? (2)
A
- Resistance to compression
- Low resistance to flexion
13
Q
What is flexion?
A
Bending strength
14
Q
Why do ceramics have low resistance to flexion? (2)
A
They lack the previous state of elastic deformation
- this is improved in high resistance porcelains
15
Q
Which ceramic is low resistance?
A
Feldspathic porcelain (empress esthetic)
16
Q
What is the resistance of feldspathic porcelins?
A
70-90 MPa
17
Q
Which ceramic is moderate resistance?
A
Lithium disilicate (E-max press/ CAD)
18
Q
What is the resistance of lithium disilicate?
A
360-400 MPa
19
Q
Which ceramic is high resistance?
A
Zirconia
20
Q
What is the resistance of zirconia?
A
900 MPa
21
Q
What materials are classified as vitreous ceramics? (3)
A
- Feldspathic
- Leucite
- Lithium disilicate
22
Q
What materials are classified as crystalline ceramics? (2)
A
- Aluminous
- Zirconia based (Y-ZTP)
23
Q
Whats the manufacturing methods for all ceramic crowns? (3)
A
- Layered
- Pressed
- CAD/CAM
24
Q
What strength are feldspathich viterous ceramics? (2)
A
- low strength
- high strength
25
Which are the glass matrix ceramics? (3)
- Feldspathic
- Synthetic reinforcemed
- Glass infiltrated
26
Which are the glass matrix ceramics with synthetic reinforcement? (3)
- Leucite based
- Lithium disilicate
- Fluorapatite-based
27
Which are the glass matrix ceramics that are glass infiltrated? (3)
- Alumina
- Alumina & magnesium
- Alumina & zirconia
28
What are the different polycrystalline ceramics? (4)
- Alumina
- Stabilized zirconia
- Zirconia-toughened alumina
- Alumina-toughned zirconia
29
What are the different resin matrix ceramics? (3)
- Resin nanoceramic
- Glass-ceramic in a resin interpenetrating matrix
- Zirconia-silica ceramic in a resin interpenetrating matrix
30
Which are the glass ceramics?
Feldspathic
31
Which are the glass ceramic with fillers? (3)
- Leucite reinforced
- lithium disilicate
- glass infiltrated
32
Which are the glass-free ceramics, polycrystalline? (2)
- Alumina
| - Zirconia
33
What are the high strength feldspathic porcelains? (2)
- Leucite reinforced
| - Lithium disilicate
34
What was the first all ceramic crown?
Low strength feldspathic porcelains
35
What are low strength feldspathic porcelins composed of? (3)
- Feldspar
- Quartz
- Kaolin
36
What is the purpose of the feldspar in low strength feldspathic porcelains?
Translucency
37
Quartz in low strength feldspathic porcelains?
Crystalline phase
38
What is the purpose of the kaolin in low strength feldspathic porcelains?
Plasticity
39
Low strength feldspathic porcelains have an important ___ phase
Glass
40
Main use of low strength feldspathic porcelains?
Veneering porcelain
41
Pro's of low strength feldspathic porcelains?
Esthetics
42
Con's of low strengh feldspathic porcelains
High fragility
43
When do you use leucite high strength feldspathic porcelains?
For high esthetic demand
44
What are Leucite reinforced high strength feldspathic porcelains made of?
Leucite microcrystals
45
What is the fracture strength of leucite reinforced high strength feldspathic porcelains?
120Mpa
46
What is the resistance of lithium disilicate reinforced high strength feldspathic porcelains?
360-400MPa
47
What are lithium disilicate reinforced high strength feldspathic porcelains made of?
reinforced with a higher percentage of lithium disilicate
48
Example of leucite-reinforced high strength feldspathic porcelain?
IPS empress II
49
IPS empress II?
Leucite-reinforced high strength feldspathic porcelain
50
Examples of lithium disilicate-reinforced high strength feldspathic porcelain? (3)
- IPS e.max CAD
- IPS e.max Press
- IPS e.max Press Multi
51
IPS e.max CAD?
Lithium disilicate-reinforced high strength feldspathic porcelain
52
IPS e.max Press?
Lithium disilicate-reinforced high strength feldspathic porcelain
53
IPS e.max Press Multi
Lithium disilicate-reinforced high strength feldspathic porcelain
54
Properties of IPS e.max Press? (2)
◦ Varies from HT (high translucency) to HO (high opacity).
| ◦ 400MPa
55
IPS e.max Press strength?
400 MPa
56
Properties of IPS e.max CAD?
◦ Varies from HT (high translucency) to HO (high opacity).
◦ Typical blue initial color.
◦ Gives the option for monolithic restorations
◦ Resistance of 360Mpa
57
What is the composition of aluminous porcelains?
Aluminum oxide instead of quartz
58
What are the mechanical properties of aluminous porcelains ?
Good
59
How is the translucency of aluminous porcelains ?
Low
60
What are aluminous porcelains used for?
Full cast crown copings
61
Porosity of aluminum oxides?
high
62
Is aluminous porcelain used often? Why or why not?
Diminished use due to the better properties and survival
| of LDS and Zr
63
What is the chemical composition of zirconia based porcelains?
ZrO2
64
What are the three phases of zirconia based porcelains?
- tetragonal
- monoclinic
- cubic
65
Which is the third stable phase that was developed of zirconia based porcelains
Cubic
66
What is the composition of zirconia-based porcelains?
- 95% zirconium oxide
| - 5% yttrium oxide
67
What is the chemical composition of yttrium oxide?
Y2O3
68
What is Y-TZP?
Yttrium stabilized tetragonal zirconia pollycrystals
69
Where can you find Y-TZP ?
zirconia-based porcelains
70
What kind of structure do zirconia-based porcelains have?
Totally crystalline structure
71
When does transformation toughening occur?
In zirconia-based porcelains
72
What are the phases of zirconia related to?
Transition related to temperature rise
73
Properties of partially stabilized zirconia Y-TZP? (3)
- high tensile strength
- fracture toughness
- most used in dental restorations
74
What chemicals can stabilize zirconia in zirconia-based porcelain? (2)
- Magnesium calcium
| - Cerium
75
What are the stages of zirconia-based porcelains transformation toughening? (3)
- Crack initiation
- Early stage of crack propagation
- later stage of crack propagation
76
What is in the crack initiation stage of zirconia-based porcelains transformation toughening?
A crack exists and all the particles are tetragonal
77
What is in the early stage of crack propagation of zirconia-based porcelains transformation toughening?
The tip of the crack is in the process zone surrounded by tetragonal particles transforming into monoclinic particles
The crack is surrounded by already transformed monoclinic particles
78
What is in the later stage of crack propagation of zirconia-based porcelains transformation toughening?
The crack is bigger
The tip of the crack is in the process zone surrounded by tetragonal particles transforming into monoclinic particles
The crack is surrounded by already transformed monoclinic particles
79
Examples of zirconia porcelains?
Lava Esthetic, Plus, Frame (3M Espe).
- Katana
- Zirkonzahn
80
Zirconia porcelain properties? (2)
* Very tough.
| * Very opaque
81
What are the properties of layered zirconia porcelains? (3)
* Aging (low temperature degradation).
* Chipping in 15% of the cases after 24 months.
* 25% of fractures and chipping after 31 months.
82
Which is the newly developed zirconia porcelains?
Monolithic zirconia
83
Properties of monolithic zirconia? (4)
- Stability structure
- High Biocompatibility
- No chipping complications
- Mono-blocks previously stratified
84
Reduction of monolithic zirconia porcelains?
- Tooth structure reduction between 0.5 and 1.5mm max.
| - 0.5 mm chamfer line [0.3 to 0.8 mm]
85
Examples of monolithic zirconia porcelains?
- Lava Plus
| - Lava Esthetic
86
Which examples of all ceramic crowns are layered over the investment cast? (4)
* In-Ceram® Spinell.
* Mirage® II Fiber.
* Optec-HSP®.
* Fortress®.
87
What is another name for the pressed technique?
Lost wax
88
What are the steps in the pressed technique? (2)
• 1º- Waxing of the framework or of the whole restoration,
by MILLING a block of WAX.
• 2º- Pressing the material into the space left by the melted
wax.
89
What is the advantage of the pressed technique?
Increases toughness by reducing porosity
90
Examples of the pressed technique? (2)
- IPS® Empress.
| - IPS® e.max Press
91
What is the lab procedure for CADCAM all ceramic crowns? (4)
- Scanning
- Design CAD
- Manufacturing methods
- Manufacturing final shape
92
What are the manufactiing methods for CADCAM all ceramic crowns?
- Milling
- Pressed
- Sintered
93
What are the different manufcating final shapes for CADCAM all ceramic crowns?
- Monolithic, full contour
- Cut-back technique
- Core + veneering
94
CADCAM all ceramic crowns monolithic full contour ? (4)
◦ All the volume of the restoration in one piece.
◦ Stains to individualize and for characterizations.
◦ LDS for posterior teeth should be prepared this way.
◦ Zirconia restorations should be made in full-contour to reduce the chipping
95
Zirconia all ceramic restorations should be made in ____ to reduce the chipping
full contour
96
All ceramic posterior teeth should be prepared this way...
Full contour monolithic
| with LDS
97
CADCAM all ceramic crowns cutback manfucating?
◦ Milling of cervical 2/3s of the crown.
| ◦ The rest is veneered with feldspathic porcelain
98
CADCAM all ceramic crowns Milled coping + veneering porcelain manufacturing?
For maximum esthetic results
99
What is the fracture toughness of ISO 6872?
Minimum of 100MPa
100
What is the fracture toughness of PFM?
400-600MPa
101
What is the gold standard of fracture toughness?
400-600 PFM
102
What is the compressive strength of feldspathic porcelain?
170 MPa
103
What is the bending strength of feldspathic porcelain?
50-75MPa
104
What is the bending strength of feldspathic porcelain when veneered over framework?
400MPa
105
What is the bending strength of lithium disilicate when CAM?
400 MPa
106
What is the bending strength of lithium disilicate when pressed?
400 MPa
107
What is the bending strength of zirconia?
700-900 MPa
108
The minimum acceptable marginal fit?
100 microns
109
The explorer cannot detect marginal fit misfits lower than...
100 microns
110
All ceramic crowns: What material do you choose for an anterior crown if it has a light color and enough prosthetic space?
High strength feldspathic porcelains
111
All ceramic crowns: What material do you choose for an anterior crown if it has a dark color?
```
Lithium disilicate, choosing a low translucency (LT) or
medium opacity (MO)
```
112
All ceramic crowns: What material do you choose for an anterior crown if it has unfavorable occlusion/space
Monolithic LDS or Zr
113
All ceramic crowns: why would you select HIGH TRANSLUCENCY HT (3)
* The underneath colour of the tooth is good.
* No more than 1 grade of colour modification.
* Multiple anterior restorations with the same colour of the substrate
114
All ceramic crowns: why would you select LT or MO materials? (3)
• Dark substrate of the preparation
• Colour modification of more than 1 grade
• Multiple restorations with different conditions of the
substrate
115
When do you select feldspathic porcelain for anterior veneers? (3)
* Small modifications of the shape.
* Slight modifications of the color.
* No more than 2mm lengthening of the incisal border.
116
When do you select LDS core and veneered porcelain for anterior veneers? (3)
* Important color changes: 2 to 3 grades.
* Important changes of the shape and length.
* Overbite, bruxism.
117
When do you select LDS for anterior veneers? (3)
* Important color changes: 2 to 3 grades.
* Important changes of the shape and length.
* Overbite, bruxism.
118
When is a posterior unitary crown a good option?
Premolars and posteriot restorations
119
In posterior unitary crown it is important to respect the..
volumes in order to give to the
| restoration the needed strength against mechanical loads
120
What volume does an LDS with a veneered layer, posterior unitary crown need
1.5mm
121
How can you get a better result with a zirconia with a veneered layer, posterior unitary crown
- rounded shoulder FL
- contact points in Zr and enough volume of the
functional cusps
122
When do we choose monolithic Zr restorations, posterior unitary crown ?
when the prosthetic space is
| limited, less abrasive when correctly polished
123
What materials can you use for anterior bridges?
- LDS
| - Zirconia
124
What is important to know about LDS in anterior bridges?
Maximum 3 pieces and not further than the premolar
125
What material do you use if the anterior bridge is light color and there is enough prosthetic space?
LDS, e-max press for its better mechanical properties
126
What material do you use for the anterior bridge, if it has a dark color or unfavorable prosthetic space?
zirconia based porcelain or PFM
127
What is the contraindication of anterior bridges?
unfavorable occlusion and low prosthetic space
128
What is important to know about anterior bridges and connector volume?
Require more volume of the connector to avoid fractures
129
What is the better option for posterior bridges when the material is full ceramic?
Zirconia
130
What type of zirconia can you use in posterior bridges? (2)
Monolithic or veneered
131
What type of connectors are needed for zirconia in posterior bridges?
- 9mmsquared connectors
| - 12mm squared if central connector
132
List the all ceramic crowna in order of higher esthetics/cost (4)
- Veneered zirconia
- lithium disilicate
- monolithic Zr
- PFM
133
What is the thickness of all ceramic PFM crown?
2mm
134
What is the thickness of all ceramic monolithic Zr crown?
0.3-0.8mm
135
What is the thickness of all ceramic LDS crown?
1-1.5mm
136
What is the thickness of all ceramic Veneered Zr crown?
1.5-2mm
137
What do we need to consider when selecting all ceramic crowns?
- Color of the substrate
- Type of occlusion
- prothetic space
138
What are the maximum esthetic concern indications for all ceramic crowns? (6)
- tooth fractures
- caries and restorations at anterior teeth
- color alterations
- diasthemas
- tooth malformation
- malposition
139
What are the maximum esthetic concern contraindications for all ceramic crowns? (3)
- parafunctional habits
- limited prosthetic space
- periodontal disease
140
What are the maximum esthetic concern contraindications for all ceramic crowns for patients with limited prosthetic space? (3)
- overbite
- crossbite
- edge-to-edge occlusion
141
What preparation size is needed for all cermaic crowns 3M laval plus zirconia?
0.5mm or more
142
What preparation size is needed for all cermaic crowns 3M lava esthetic zirconia?
0.8mm or more
143
What preparation size is needed for all cermaic crowns IPS e.max
1.5mm or more
144
What is an example of 3Y-TZP zirconia?
3M laval plus high-translucency
145
What minimal wall thickness is needed for material stability of of 3Y-TZP zirconia anteriorly?
0.3mm
146
What minimal wall thickness is needed for material stability of of 3Y-TZP zirconia posteriorly?
0.5mm
147
What minimal wall thickness is needed for material stability of of 4Y-TZP zirconia anteriorly?
0.8mm
148
What minimal wall thickness is needed for material stability of of 4Y-TZP zirconia posteriorly?
0.8mm
149
What is an example of 4Y-TZP zirconia
3M chairside zirconia
150
What is an example of 5Y-TZP full contour zirconia
3M™ Lava™ Esthetic Fluorescent Full-Contour
| Zirconia
151
What is an example of lithium disilicate? (2)
- IPS e-max CAD
| - ivoclar vivadent
152
What minimal wall thickness is needed for material stability of of 5Y-TZP zirconia posteriorly?
0.8mm
153
What minimal wall thickness is needed for material stability of 5Y-TZP zirconia anteriorly?
0.8mm
154
What minimal wall thickness is needed for material stability of LDS anteriorly?
1.0-1.5mm
155
What minimal wall thickness is needed for material stability of LDS posteriorly?
1.0-1.5mm
156
What minimal wall thickness is needed for material stability of 3Y-TZP zirconia plus veneering porcelain anteriorly?
1.5-2.0mm
157
What minimal wall thickness is needed for material stability of 3Y-TZP zirconia plus veneering porcelain posteriorly?
1.5-2.0mm
158
Example of 3Y-TZP zirconia plus veneering porcelain?
3M™ Lava™ Frame Zirconia
159
What minimal wall thickness is needed for material stability of PFM posteriorly?
1.5-2.0mm
160
What minimal wall thickness is needed for material stability of PFM anteriorly?
1.5-2.0mm
161
What abutment height is needed for all ceramic crowns if conventional cementation is desired?
4mm
162
Which angles are not read correctly by scanning machines?
Straight
163
Allceramic crowns: material favorable in the posterior region?
- monolithic
| - high strength ceramics
164
Allceramic crowns: material favorable in the anterior region?
layered/hand veneered ceramics
