Lithium disilicate glass-ceramic, method for production thereof and use thereof

Abstract

The invention relates to glass-ceramics based on the lithium silicate system which can be mechanically machined easily in an intermediate step of crystallization and, after complete crystallisation, represent a very strong, highly-translucent and chemically-stable glass-ceramic Likewise, the invention relates to a method for the production of these glass-ceramics. The glass-ceramics according to the invention are used as dental material.

1 . (canceled) 
     
     
         2 . A method of producing a shaped lithium disilicate dental product, comprising:
 a) producing an initial glass, wherein the amount of SiO 2  is 55 to 70 weight percent, the amount of Li 2 O is 10 to 15 weight percent, the amount of K 2 O is 0.1 to 5 weight percent, the amount of A1203 is 0.1 to 5 weight percent, the amount of P 2 O 5  is 2 to 5 weight percent, and the amount of ZrO 2  is at least 10.0 weight percent, wherein the total weight percent is 100 weight percent;   b) subjecting the initial glass to a first heat treatment in order to produce a glass-ceramic which has lithium metasilicate as the main crystal phase;   c) forming a shaped dental product out of the glass-ceramic; and   d) forming a shaped lithium disilicate dental product by subjecting the shaped dental product to a second heat treatment in which the lithium metasilicate is converted with SiO 2  from the glass phase into lithium disilicate and subsequently lithium disilicate is present as the main crystal phase.