METHOD OF OBTAINMENT OF TOOTH PROSTHESES Russian patent published in 2018 - IPC A61K6/27 C03C4/00 C03C10/00 

FIELD: medicine.

SUBSTANCE: group of inventions refers to methods for obtaining the dental prosthesis based on lithium silicate glass or lithium glass ceramics. Methods include the step of melting the powder mixture of the following composition (weight%): SiO₂ 50–70, Li₂O 5–25, Al₂O₃ 0.1–20, K₂O 0.1–15, CeO₂ 0.1–15, B₂O₃ 0–5, P₂O₅ 0–15, Tb₂O₃ 0–2, ZrO₂ 0–15, ZnO 0–4, comprising also 0.1–5% of at least one additive from the group BaO, CaO, MgO, MnO, Er₂O₃, Gd₂O₃, Na₂O, Pr₂O₃, Pr₆O₁₁, Sm₂O₃, TiO₂, V₂O₅, Y₂O₃. In this case, one of the method options comprises the following technological steps: the preparation of solidified melt of the spherical or lens-like glass particles; portioning of glass particles and filling them with the casting crucible; melting of glass particles in the casting crucible and setting the viscosity v in the following interval 4 dPa∙s ≤ v ≤ 80 dPa∙s; casting the resulting melt into the negative mould that is surrounded by the investment material, corresponding to the dental prosthesis; melt curing in the negative mould; crystallization of lithium metasilicate as the main crystalline phase from the solidified melt as the result of applying of at least one first heat treatment at the temperature from 600 to 760 °C for the period of from 20 to 120 minutes, wherein the heat treatment of the solidified melt is carried out either in the negative mould, or after extraction from the negative mould; crystallization of lithium disilicate as the main crystalline phase during the second heat treatment at the temperature from 760 to 860 °C for the period from 5 to 60 minutes. Another method option is carried out bymeans of centrifugal casting or injection molding into the vacuum molds.

EFFECT: use of the group of inventions provides for the easy-to-use source material for the production of prostheses and the reproducible obtainment of dental protheses based on lithium silicate glass or lithium glass ceramics by means of casting.

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