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US 11,583,374 B2Granted
Process for the preparation of a glass-ceramic blank for dental purposes
AssigneeIvoclar Vivadent AG
InventorChristian Ritzberger
Life of this patent
Estimating the term…
Abstract
The invention relates to a process for the preparation of a glass-ceramic blank for dental purposes with lithium silicate as crystal phase, in which lithium silicate blanks that are no longer required and in particular residues thereof are used as starting material and which allows the production of a homogeneous starting glass within a short time.
Claims17
Process for the preparation of a glass-ceramic blank for dental purposes with lithium silicate as crystal phase, comprising
- (a) lithium silicate blanks with different chemical composition or residues of lithium silicate blanks with different chemical composition are melted to form a glass,
- (b) optionally, the molten glass is converted into a glass frit and the glass frit is melted to form a glass,
- (c) the glass from step (a) or (b) is shaped into a glass blank,
- (d) the glass blank is heat-treated at a temperature of 450 to 600° C. in order to form a glass blank with nuclei,
- (e) the glass blank with nuclei is subjected to a heat treatment at a temperature of 600 to 850° C. in order to form a glass-ceramic blank with lithium metasilicate as crystal phase, or is subjected to a heat treatment at a temperature of 700 to 1000° C. in order to form a glass-ceramic blank with lithium disilicate as crystal phase,
- (f) optionally, the glass-ceramic blank with lithium metasilicate as crystal phase from step (e) is subjected to a heat treatment at a temperature of 700 to 1000° C. in order to form a glass-ceramic blank with lithium disilicate as crystal phase, and
- (g) optionally, in step (a) and/or (b) at least one chemical compound is added in order to change the chemical composition of the glass and/or of the glass frit.
4 more elements
Process for the preparation of dental restorations, in which a glass-ceramic blank is prepared by the process comprising
- (a) lithium silicate blanks with different chemical composition or residues of lithium silicate blanks with different chemical composition are melted to form a glass,
- (b) optionally, the molten glass is converted into a glass frit and the glass frit is melted to form a glass,
- (c) the glass from step (a) or (b) is shaped into a glass blank,
- (d) the glass blank is heat-treated at a temperature of 450 to 600° C. in order to form a glass blank with nuclei,
- (e) the glass blank with nuclei is subjected to a heat treatment at a temperature of 600 to 850° C. in order to form a glass-ceramic blank with lithium metasilicate as crystal phase, or is subjected to a heat treatment at a temperature of 700 to 1000° C. in order to form a glass-ceramic blank with lithium disilicate as crystal phase,
- (f) optionally, the glass-ceramic blank with lithium metasilicate as crystal phase from step (e) is subjected to a heat treatment at a temperature of 700 to 1000° C. in order to form a glass-ceramic blank with lithium disilicate as crystal phase, and
- (g) optionally, in step (a) and/or (b) at least one chemical compound is added in order to change the chemical composition of the glass and/or of the glass frit, and
- wherein the glass-ceramic blank prepared is given the shape of the dental restorations by pressing or machining.
5 more elements
Dependencies are inferred from the claim text.