GYPSUM-BASED CASTING EMBEDDING MATERIAL FOR DENTAL USE

摘要

PROBLEM TO BE SOLVED: To obtain a gypsum-based casting embedding material for dental use having good operability and dig-out property at the time of casting in high temp. and excellent high temp. casting characteristic without deformation and change with time caused by residual stress. SOLUTION: In this gypsum-based casting embedding material containing a heat resistant material and a hemihydrate gypsum as binder, the heat resistant material is composed of MgO.Al2 O3 spinel and the hemihydrate gypsum as the binder. In this case, 0.5-20 pts.wt. of gypsum whisker as a shrinkage inhibitor and 0.5-5 pts.wt. of ZrC or TiC as an expanding agent are added externally to 100 pts.wt. of the embedding material.