| abstract |
(57) [Abstract] [Purpose] To obtain a dental gypsum composition which has good compatibility with an agar-based aqueous colloid impression material and gives a plaster model without surface roughness. [Composition] Hemihydrate gypsum is blended with an alkali metal tartrate, sugar alcohols such as D-mannite and D-sorbit, and a set retarder such as Na citrate. [Effect] Even when an agar-based or alginic acid-based impression material is used, a gypsum model having a small surface roughness and excellent dimensional accuracy and mechanical strength can be obtained. |