Gypsum
From WikiDent
[edit]
ADA Specification 25
| Type | Description | Setting time (min) | Min % | Max % | Water-powder ratio |
|---|---|---|---|---|---|
| I | Plaster, impression | 4 ± 1 | 0.00 | 0.15 | 0.50-0.75 |
| II | Plaster, model | 12 ± 4 | 0.00 | 0.30 | 0.45-0.50 |
| III | Dental stone | 12 ± 4 | 0.00 | 0.20 | 0.28-0.30 |
| IV | Dental stone, high strength | 12 ± 4 | 0.00 | 0.10 | 0.22-0.24 |
| V | Dental stone, high strength, high expansion | 12 ± 4 | 0.10 | 0.30 | 0.18-0.22 |
