Dental Ceramics

Question 1

CERAMICS

Answer 1

▸ of or relating to the manufacture
of any product made essentially
from minerals by firing at a high
temperature

Question 2

PORCELAIN

Answer 2

▸ a ceramic material composed
(mainly) of feldspar, quartz, and
kaolin
70-90% Feldspar:
potassium aluminum silicate K2O·Al2O3·6SiO2
10-20% Quartz: high-fusing SiO2
1-10% Kaolin: clay
Coloring frits

Question 3

ADVANTAGES OF DENTAL CERAMICS
(4)

Answer 3

▸ Esthetics
▸ Biocompatibility
▸ Preservation of tooth structure
▸ Strength

Question 4

▸ — is one of the primary indication for using dental ceramics and all-ceramic
restorations
▸ Some ceramic materials mimics the — properties of natural tooth structure
▸ Translucency:
▸ Superior optical properties compared to — restorations

Answer 4

Esthetics
optical
light can penetrate the material (enamel’s translucency is 70%, dentin’s 30%)
PFM

Question 5

▸ Ceramics are …
▸ Low affinity for attracting and retaining — to
Metal alloys can cause tissue —
due to release of metallic ion

Answer 5

biocompatible and bio-inert (no cellular/tissue response)
plaque
discoloration

Question 6

PRESERVING TOOTH STRUCTURE
▸ More conservative preparations are possible with all-ceramic
restorations as compared to metal-ceramic restorations
(2)

Answer 6

▸ advantages of bonding with all-ceramic restorations (Strassler HE. Gen Dent. 2007)
▸ less likelihood for need of endodontic treatment (Goodacre et al. J Prosthet Dent 2003)

Question 7

▸ The strength of ceramic materials is measured by the …
▸ Current ceramics have values in the range of — MPa
▸ Use of — cements increase the fracture resistance of the restoration

Answer 7

flexural strength (MPa)
250-1500
resin-bonding

Question 8

LIMITATIONS OF DENTAL CERAMICS
▸ Limited interocclusal space:
▸ Heavy occlusal forces:
▸ Sub-gingival preparations:
▸ Discolored teeth

Answer 8

anterior and posterior
History of parafunctional habits (bruxism)
where bonding of restoration is not effective

Question 9

CLASSIFICATION OF DENTAL CERAMICS
Based on:
(4)

Answer 9

▸ Fusing temperature
▸ Utilization
▸ Laboratory processing
▸ Composition

Question 10

BASED ON UTILIZATION
▸ Core ceramics:
▸ Opaquer ceramics:
▸ Veneering ceramics:

Answer 10

Support and reinforces the restoration
Mask and cover metallic structures
Body, Incisal, Gingival, Translucency

Question 11

BASED ON LABORATORY PROCESSING
(5)

Answer 11

▸ Sintering
▸ Casting
▸ Heat pressed
▸ Glass infiltration
▸ CAD/CAM

Question 12

BASED ON COMPOSITION
▸Predominately Glass
(1)
▸Particle-filled Glass Ceramics
(2)
▸Polycrystalline Ceramics
(2)

Answer 12

• Feldspathic (1910)
• Leucite (1980’s until late 1990’s)
• Lithium Disilicate (2000’) (e.max)
• Alumina (1990’)
• Zirconia (2000’

Question 13

Lithium Disilicate (e.max)
▸ — ceramic
▸ Key ingredients: - Feldspar (glassy matrix), - Li-Disilicate (crystal filler) ~–%/vol
▸ Strength: ~— MPa

Answer 13

Glass-based
70
250-500

Question 14

Lithium Disilicate (e.max)
How it’s made: (2)

Answer 14

• Pressed, - Milled (CAD/CAM)

Question 15

Lithium Disilicate (e.max)
Indications:
(5)

Answer 15

▸ Veneers
▸ Inlays/ Onlays
▸ Crowns
▸ 3-unit FPDs: Anterior/Premolar?
▸ Implant restorations (single units)

Question 16

Zirconia
▸ How it’s made: -
▸ Strength: — MPa
▸ Can be used as a framework that accepts feldspathic veneering porcelain
▸ Low — and inferior —
▸ Bonding?

Answer 16

Milled (CAD/CAM)
800-1500
translucency, esthetics

Question 17

Zirconia
Indications:
(4)

Answer 17

▸ Crowns
▸ FPDs: anterior or posterior
▸ Implant restorations
▸ Frameworks

Question 18

Possible Reasons for Failure/Fracture of All-Ceramic Restorations
(4)

Answer 18

▸ 10% of higher mismatch in CTE between the core ceramic and
veneering porcelain (pertains to non-monolithic restorations)
▸ Residual stresses within the ceramic (fast cooling or aggressive adjustments
after sintering)
▸ Inadequate material thickness (inadequate tooth preparation/reduction, sharp
angles, etc)
▸ Inadequate planning (parafunctional habits, bruxism, etc)