Chapt 9 Gypsum Products

Question 1

Calcination

Answer 1

The process of heating a solid material to drive off volatile (揮發性) chemically combined components. ex: water and CO₂.

Question 2

Cast

Answer 2

A reproduction of the shape and surface of a structure made in an impression of the surface.

Question 3

Dental plaster (plaster of Paris)

Answer 3

The beta form of calcium sulfate hemihydrate (CaSO₄ 12H₂O).

Question 4

Dental stone

Answer 4

The alpha form of calcium sulfate hemihydrate (CaSO₄ 12H₂O).

Question 5

Die

Answer 5

A reproduction of a prepared tooth made from a gypsum product.

Question 6

Gypsum

Answer 6

Calcium sulfate dihydrate (CaSO4●2H₂O).

Question 7

Gypsum-based investment

Answer 7

A refractory material (耐火材料) consisting of silica and gypsum as a binder used to produce a mold for the metal casting process.

Question 8

Hygroscopic setting expansion

Answer 8

The expansion that occurs when gypsum or a gypsum-bonded investment sets while immersed in water usually heated to approximately 38 C

Question 9

Model

Answer 9

A positive likeness of an object.

Question 10

Normal setting expansion

Answer 10

The expansion that occurs when gypsum or a gypsum-bonded investment sets in ambient air.