Zirconia Crowns

Question 1

A type of metal which is long lasting and indestructible. White powdered metal used to crest dental frameworks for crowns, bridges, etc.

Answer 1

Zirconia

Question 2

Inidications for Zirconia Crown:

Answer 2

1. Ant/Post crowns and bridges
2. Post and core (endo)
3. Implants abutments
4. Ortho brackets

Question 3

Contraindications for Zirconia Crown:

Answer 3

1. Reduced inter occlusal space
2. Deep vertical overlap
3. Opposing supra erupted tooth
4. Very short clinical crown

Question 4

Advantages to Zirconia:

Answer 4

1. Superior esthetics
2. Easy preparation/cementation
3. Optimal fit (CAD/CAM)
4. High strength (fracture/crack resistance, good flexural strength)
5. Excellent insulating behavior
6. Biocompatible

Question 5

Porcelain fused to metal (PFM/MCC) cons

Answer 5

1. Increase opacity
2. Porcelain chips off
3. Marginal discoloration

Question 6

Disadvantages of Zirconia

Answer 6

1. Expensive
2. Difficult to reinterpret vine (posts for endo)
3. Bond between veneer ceramic and zirconia framework is the weakest component in the layered structure
4. Non available longitudinal study

Question 7

For a Zirconia prep, How much should be reduced:

1. Occlusal?
2. Mesial/Distal?
3. Buccal/Lingual?
4. Chamfer width?
5. Degree of taper?

Answer 7

1. 1.5 mm
2. 1.0
3. 1.0
4. 1.0
5. 6 degrees