The invention relates to the use of lithium silicate glass ceramics and glasses with rubidium oxide content for coating an oxide ceramic, a metal or an alloy.

ZrO.sub.2-toughened glass ceramics having high molar fractions of tetragonal ZrO2 and fracture toughness value of greater than 2 MPa.Math.m.sup.1/2. The glass ceramic may also include also contain other secondary phases that may be beneficial for toughening or for strengthening through an ion exchange process. Additional second phases may also decrease the coefficient of thermal expansion of the glass ceramic. A method of making such glass ceramics is also provided.

Pre-sintered blanks based on lithium metasilicate glass ceramic are described which are suitable in particular for the preparation of dental restorations.

To provide a phosphate-based dental investment material which can used for metal and press ceramic and especially can impart the lubricity to the surface of a press ceramic, and a phosphate-based dental investment material which can be subjected to a flash heating for press ceramic, can obtain sufficient the hardening expansion, and can easily remove the investment material after press molding. A phosphate-based dental investment material of the present disclosure comprising a powder material and a liquid material, wherein the powder material contains (a) magnesium oxide: 5 to 20 wt. %; (b) ammonium dihydrogenphosphate: 8 to 25 wt. % and the liquid material contains (c) aqueous solution including a cation-treated colloidal silica.

The present invention relates to a process for producing a workpiece made of glass ceramics, and to the workpiece obtainable by the process according to the invention. Further, the invention relates to the use of the workpiece obtained as a dental restoration, and to a process allowing the translucency of a workpiece to be controlled.

The invention relates to a process for preparing dental restorations, wherein a lithium silicate glass ceramic or a lithium silicate glass is used which contains at least 8.5 wt.-% transition metal oxide selected from the group consisting of oxides of yttrium, oxides of transition metals with an atomic number from 41 to 79 and mixtures of these oxides.

A leucite glass-ceramic is prepared from a glass comprising: about 66.8 to about 71.9 mol % of SiO.sub.2, about 8.5 to about 10.6 mol % of Al.sub.2O.sub.3, about 9.5 to about 12.8 mol % of K.sub.2O, about 0.5 to about 4.0 mol % of CaO, about 0 to about 3.0 mol % of TiO.sub.2, about 1.8 to about 4.0 mol % of Na.sub.2O, about 0.1 to about 6.0 mol % of Li.sub.2O, about 0 to about 1.0 mol % of MgO, about 0 to about 3.0 mol % of Nb.sub.2O.sub.5, and about 0 to about 3.0 mol % of B.sub.2O.sub.3. The leucite glass-ceramic is prepared by subjecting the glass components to a nucleation heat treatment, followed by a growth heat treatment. The leucite glass-ceramic may be used in the fabrication of a Dental restoration using various processes, and may be used in the construction of Dental restorations such as ceramic Dental inlays, crowns, veneers, bridges, veneering materials for zirconium oxide restoration substrates, alumina oxide restoration substrates, or metal restoration substrates.

Pre-sintered blanks based on lithium metasilicate glass ceramic are described which are suitable in particular for the preparation of dental restorations.

The present invention provides a process for preparing a dental restoration comprising the following steps: (a1) providing a dental glass ceramics mill blank and machining an indirect dental restoration from the mill blank, or (a2) providing a dental glass ceramics press blank and pressing an indirect dental restoration from the press blank; and (b) heat treating the indirect dental restoration obtained in step (a1) or (a2) at a temperature below the melting point of the dental glass ceramics for at least 15 seconds by irradiating light having a wavelength in the range of 350 to 500 nm, for preparing the dental restoration.

Moreover, the present invention provides a dental furnace, in particular for use in the process of the present invention.

The present invention provides a process for preparing a dental restoration comprising the following steps: (a1) providing a dental glass ceramics mill blank and machining an indirect dental restoration from the mill blank, or (a2) providing a dental glass ceramics press blank and pressing an indirect dental restoration from the press blank; and (b) heat treating the indirect dental restoration obtained in step (a1) or (a2) at a temperature below the melting point of the dental glass ceramics for at least 15 seconds by irradiating light having a wavelength in the range of 350 to 500 nm, for preparing the dental restoration.

Moreover, the present invention provides a dental furnace, in particular for use in the process of the present invention.