LITHIUM-SILICATE GLASS-CERAMICS AND GLASS WITH TETRAVALENT METAL OXIDE Russian patent published in 2017 - IPC A61K6/02 C03C3/76 C03C3/83 C03C3/95 C03C3/97 C03C4/00 C03C10/00 

FIELD: chemistry.

SUBSTANCE: method for manufacturing a lithium silicate glass-ceramic comprising: a tetravalent metal oxide selected ZrO₂, TiO₂, CeO₂, GeO₂, SnO₂ and mixtures thereof, of at least 12.1 wt % Li₂O_, from 0 to less than 0.1 wt % of La₂O₃, from 0 to less than 1.0 wt % of K₂O and less than 2.0 wt % of Na₂O_, comprises the steps of: (a) the initial glass comprising the components of the glass-ceramic is subjected to a thermal treatment at a temperature of 480-520°C for 10-30 min to form a glass with embryos that are suitable for the formation of lithium disilicate crystals, and (b) glass with embryos is subjected to heat treatment at a temperature of 640-740°C for the formation of glass ceramics with lithium disilicate as the main crystalline phase, the duration of the second heat treatment in step (b) is 10-60 minutes. Lithium silicate glass ceramics obtained by the aforementioned method and using it as a material for tooth restoration, in particular for coating materials for restoration of teeth or for the manufacture of materials for restoration of teeth, is also proposed.

EFFECT: preparation of glass ceramics containing lithium disilicate as the main crystalline phase, with short thermal treatments and at sufficiently low temperatures of the crystallization process, the formation of the resulting glass ceramics into the desired material for tooth restoration can be carried out by pressing or machining.

21 cl, 1 tbl, 16 ex