Gypsum Products: Uses And Composition

Gypsum Products: Uses And Composition

Classify gypsum products. Describe the difference between alpha and beta hemihydrates and their uses.
Or
Classify gypsum products.
Or
Write the difference between α and β hemihydrates.
Or
Classify gypsum products used in dentistry and Differentiate between dental plaster and dental stone.
Answer:

Classification of Gypsum Products

ISO 6873:2013:

• Type 1: Dental plaster for impressions
• Type 2: Dental plaster
  • Class 1: For mounting
  • Class 2: For models
• Type 3: Dental stone for models
• Type 4: Dental stone (high strength, low expansion)
  for dies
• Type 5: Dental stone (high strength, high expansion)
  for dies.

According to ANSI/ADA specification no. 25:

Difference between Alpha Hemihydrate and Beta Hemihydrate:

Uses of Alpha Hemihydrate:

• Uses of alpha hemihydrate:
  • For preparing the master cast.
  • For making mould.
• Uses of beta hemihydrates:
  • For making study cast and models.
  • For making moulds, for curing dentures
  • For mounting casts on articulator.