High strength ceramic restorations

Question 1

What are the ways that creamic restorations can be supported for added strengh?

Answer 1

Resin bonded
PFM use metal substructure for support
High strength ceramic for support

Question 2

How are substructures produced in high-strength ceramic? How did they used to be produced?

Answer 2

CADCAM
Slip-casting was used prior
Ceramics sintered to the substructure

Question 3

What are zirconia substructure materials?

Answer 3

Yttrium stabilised zirconia which are machined in pre-sintered state
Milled to 20% oversize to compensate for the shrinkage that occurs during firing
e.g. Procera, lava, zircon zahn

Question 4

What are the different glass infiltrated substructure materials?
How are they formed?

Answer 4

Inceram;
Spinell - translucent but not strong, just for anteriors
Alumina- translucent, strong, single units and anterior bridges
Zirconia - very strong, bridge frameworks
Produced from blocks of lightly sintered material once shaped the material is glass infiltrated

Question 5

What are the advantages of glass infiltrated substructure materials?

Answer 5

Aesthetic
Strong
Simple to produce
biocompatible

Question 6

What are the disadvantages of glass infiltrated substructure materials?

Answer 6

Expensive equipment needed 
Confusing choice of materials and production methods
Varying strengths 
Varying optical properties 
Expensive