6Ceramics

Question 1

What materials are used as pigments in ceramics?

Answer 1

Metallic Oxides

Question 2

What are the two phases of feldspathic dental porcelain after manufacture? Which phase has the high thermal expansion, contributes to strength, and 10-20% controls the CTE of the porcelain?

Answer 2

1. Vitreous (glass) and 2.Crystalline (mineral/leucite)….2.Crystalline has the high thermal expansion, contributes to strength, and 10-20% controls the CTE of the porcelain

Question 3

_______ is the heating of porcelain under a vacuum. The porcelain particles join together by flow on contact as a result of ________. The first firing is the _________.

Answer 3

SINTERING!…Surface Energy….Biscuit Bake

Question 4

What is the most susceptible portion of a PFM to fracture?

Answer 4

The porcelain and metal junction

Question 5

Fractures at the metal-metal oxide layer are commonly observed with poor ______.

Answer 5

Bonding

Question 6

Fracture through the _____ layer – base metals commonly fx here if layer is too thick.

Answer 6

oxide

Question 7

Proper bonding – highest strength ceramic-metal specimens fracture in the _______.

Answer 7

porcelain

Question 8

Which is Greater? Metal CTE OR Porcelain CTE?

Answer 8

Metal Coefficient of Thermal Expansion > Porcelain

Question 9

CTE of ceramic and metal must be compatible – metal slightly higher than ceramic to put ceramic in _______ where it is stronger.

Answer 9

compression