Combination of silica phosphate and gypsum bonding material used in dentistry to enclose wax or plastic patterns during the casting process in the laboratory fabrication of dental crowns and bridges. For lower casting temperatures, a gypsum bonding material is used, and for higher casting temperatures, phosphates or silica materials are used.
A material combining principally a form of silica and a bonding agent. The bonding substance may be gypsum or silica phosphate according to the casting temperature.