Category: Gypsum Products

A. Tensile strength
B. Wet strength
C. Green strength
D. compressive strength

A. Modify setting time
B. Modify setting expansion
C. Modify strength
D. Decrease the porosity

A. H2O interferes with hygroscopic expansion
B. H2O inhibits polymerization of dental resin
C. H2O interferes with Crystallization of dihydrate
D. Gypsum is slightly soluble in water and the surface of the cast will be eroded

A. Testing the strength of plaster of paris
B. Evaluating the setting time of plaster of pris
C. Testing the metal hardness
D. Testing the purity of noble metals

A. Difference in solubility of CaSo4 ½ H2O + CaSO4+ 2H2O
B. Reaction between CaSO4+ 2H2O and water
C. Nucleation and growth of CaSo4 ½ H2O crystals
D. Reaction between hemihydrate and hihydrate

A. Na2 So4
B. Nacl
C. Citrales
D. K₂ So₄

A. Investment
B. Hydrocolloids
C. Amalgam
D. Silicate

A. Alpha – hemihydrates
B. Beta – hemihydrates
C. Calcium sulphate dihydrate
D. Orthorhombic anhydrate

A. Not waiting for 20 min before pouring
B. High speed accelerator
C. Air incorporation in the mix
D. All of the above

A. Impressions
B. Casts
C. Die
D. Casts and Dies