DENTAL RESTORATION MATERIAL, METHOD FOR PRODUCTION THEREOF AND GLASS CERAMIC Russian patent published in 2017 - IPC A61K6/27 C03B32/02 C03C10/00 

FIELD: manufacturing technology; chemistry.

SUBSTANCE: group of inventions relates to glass-ceramic materials for making dental restoration material, a method of producing said material, as well as to dental restoration material. According to a method for making dental restoration material, containing glass ceramic based on lithium silicate, amorphous glass of following composition, in wt%: SiO₂ 55–70, Li₂O 17–20, ZrO₂ 8–20, Al₂O₃ 0–8 %, K₂O 0–8 % and additives 0–15 %, is subjected to at least one thermal treatment, which is a two-step treatment with first temperature of 600 to 800 °C, and second temperature of 780 to 900 °C, to produce tooth-coloured glass ceramics, transmitting light with wavelength of 360 nm to 740 nm (according to measurement in accordance with DIN EN 410 on a Minolta CM-3610d spectrometer), with strength of at least 250 MPa (measured in accordance with DIN ISO 6872), and having colour of tooth, wherein during said at least a single thermal treatment there is at least partial crystallisation owing to high temperatures. Said glass-ceramic is used to produce dental restoration material by a material removal process, selected from a group consisting of cutting, grinding and laser ablation, and before dental application, dental restoration material is subjected to final processing, which is polishing, glazing, sealing, coating and lining with facing ceramic or glaze, wherein strength of dental restoration material is at least 250 MPa (measured in accordance with DIN ISO 6872). Also disclosed is a dental restoration material produced by said method, and tooth-coloured glass ceramics for making dental restoration material, which transmits light with wavelength of 360 nm to 740 nm (according to measurement in accordance with DIN EN 410 on a Minolta CM-3610d spectrometer), having strength of at least 250 MPa (measured in accordance with DIN ISO 6872) and having following composition, wt%: SiO₂ 55–70, Li₂O 17–20, ZrO₂ 8–20, Al₂O₃ 0–8 %, K₂O 0–8 % and additives 0–15 %.

EFFECT: use of group of inventions enables to obtain dental restoration material, having high strength and chemical resistance, which is machinable.

12 cl, 3 tbl, 2 ex