Patent ID: 7867931

Claim:
A lithium silicate glass ceramic which comprises lithium disilicate as the main crystalline phase which comprises the following components: Component wt.-% SiO 2 64.0-75.0 Li 2 O 13.0-17.0 K 2 O 2.0-5.0 Al 2 O 3 0.5-5.0 Nucleating agent 2.0-5.0 Me(II)O 0-3.0 ZrO 2 0.1-4.0 and which comprises less than 0.1 wt. % of ZnO, with Me(II)O being selected from at least one of CaO, BaO, MgO and SrO wherein the glass ceramic exhibits a contrast ratio below 0.80 and a flexural strength greater than about 500 MPa.