Gypsum products Flashcards
1
Q
Types of Gypsum
A
Types I, II, III, IV, V.
2
Q
Type I Gypsum
A
Impression plaster
3
Q
Type II Gypsum
A
Model plaster / dental plaster
4
Q
Type III Gypsum
A
Dental stone
Hydro cal
Class I stone
5
Q
Type IV Gypsum
A
Class II Dental stone
Improved dental stone
Densite
High strength dental stone
6
Q
Type V Gypsum
A
- Dental stone with high strength and high expansion
- Extra hard, improved dental stone
7
Q
W/P Ratio for Impression plaster
A
0.5 - 0.75
8
Q
W/P Ratio for Gypsum type II
A
0.45 - 0.50
9
Q
W/P Ratio for hydro cal
A
0.28 - 0.30
10
Q
W/P Ratio for densite
A
0.22 - 0.24
11
Q
W/P Ratio for extra hard, improved dental stone
A
0.18 - 0.22
12
Q
Setting time - Gypsum type I
A
4 - 5 minutes
13
Q
Setting time - Gypsum types II, III, IV, V
A
12 - 15 minutes
14
Q
Setting expansion for impression plaster
A
0.15%
15
Q
Setting expansion for model plaster
A
0.30%
