Patent ID: 6342302
Filing Date: 2002-01-29
Classification: A61K,C03C

Abstract:
A molded ceramic dental restoration comprising a ceramic base faced with a dental facing ceramicwherein said ceramic base is a leucitic glass-ceramic, comprising 40-95wt.-%SiO25-25wt.-%Al2O35-25wt.-%K2O0-25wt.-%Na2O0-20wt.-%CaO0-8wt.-%B2O30-0.5wt.-%P2O50-3wt.-%F,â€ƒand containing, as the sole crystalline phase, leucite in a total proportion from 20 to 45 wt.-%, at least 80% of the theoretically producible quantity of leucite being present, and in which glass ceramic exhibits a linear coefficient of thermal expansion &agr;(20-500Â° C.) from 12.5Â·10âˆ’6 to 15.5Â·10âˆ’6 Kâˆ’1, and wherein said dental ceramic exhibits a linear coefficient of thermal expansion &agr;(20-500Â° C.) from 13.5Â·10âˆ’6 to 17.0Â·10âˆ’6 Kâˆ’1, the coefficient thermal expansion of said glass ceramic being chosen so that lies 0.5Â·10âˆ’6 to 2.5Â·10âˆ’6 Kâˆ’1 below that of the facing-ceramic.