abstract |
Lithium silicate glass ceramic, containing a pentavalent metal oxide selected from Nb2O5, Ta2O5 and mixtures thereof and containing between 11.0 and 21.0% by weight of Li2O and less than 2.0% by weight of K2O , less than 1.0% by weight of Na2O and less than 0.5% by weight of CaO. |