Lithium Silicate Glass Ceramic And Glass With Divalent Metal Oxide
AssigneeIvoclar Vivadent AG
InventorsChristian Ritzberger, Elke Apel, Wolfram Höland, Volker Rheinberger
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Abstract
Lithium silicate glass ceramics and glasses containing specific oxides of divalent elements are described which crystallize at low temperatures and are suitable in particular as dental materials.
Claims23
Lithium silicate glass ceramic which comprises a divalent metal oxide selected from MgO, CaO, SrO, BaO, ZnO and mixtures thereof and comprises at least 12.1 wt.-% Li2O and less than 1.0 wt.-% K2O and which comprises lithium metasilicate as a main crystal phase.
Process for the preparation of a lithium silicate glass ceramic which comprises a divalent metal oxide selected from MgO, CaO, SrO, BaO, ZnO and mixtures thereof and comprises at least 12.1 wt.-% Li2O and less than 1.0 wt.-% K2O, wherein
- (a) a starting glass is subjected to a heat treatment at a temperature of from 470 to 560° C. in order to form the glass with nuclei, and
- (b) the glass with nuclei is subjected to a heat treatment at a temperature of from 600 to 750° C. in order to form the glass ceramic with lithium disilicate as main crystal phase.
A process of using a lithium silicate glass ceramic which comprises a divalent metal oxide selected from MgO, CaO, SrO, BaO, ZnO and mixtures thereof and comprises at least 12.1 wt.-% Li2O and less than 1.0 wt.-% K2O as dental material, wherein the glass ceramic is shaped by pressing or machining to a desired dental restoration.
Dependencies are inferred from the claim text.