Dental Porcelain

Question 1

What is the difference between Crystalline and Amorphous structure?

Answer 1

Crystalline: atoms arranged in organised manner throughout material

Amorphous:
Atoms not arranged in orderly form

Question 2

What is Fracture Toughness?

Answer 2

Ability of material to resist crack propagation

Question 3

How do you increase Fracture toughness?

Answer 3

Add fillers
- inhibits crack propagation by creating torturous crack path

Question 4

What characteristics of the filler affect crack propagation?

Answer 4

1. Size of filler
2. Distribution of filler

Question 5

The term ‘polycrystalline’ is used to describe..

Answer 5

Ceramic framework (only that and nothing else in DM)

Question 6

What is a Glaze?

Answer 6

Coat of glass to seal surface defects
- liquid glass, flows very nicely

Question 7

How is the colour stability of ceramics?

Answer 7

Crazy high!
- colour of ceramics wont change one
- but surface defects can affect colour stability (when ceramic is rough, molecules have places to lodge in )