23-01-2020 дата публикации
Номер: US20200024181A1
Принадлежит:
Lithium silicate materials are described which can be easily processed by machining to dental products without undue wear of the tools and which subsequently can be converted into lithium silicate products showing high strength. 1. A lithium silicate glass ceramic for dental restorations which comprises a main crystalline phase comprising lithium metasilicate , wherein the lithium metasilicate crystals comprise lamellar or platelet crystals.2. The lithium silicate glass ceramic of claim 1 , wherein the lithium metasilicate forms more than 50 and up to 80 vol. % of the lithium silicate glass ceramic.3. The lithium silicate glass ceramic of claim 1 , wherein the glass ceramic is in form of a blank or a dental restoration.4. The lithium silicate glass ceramic of claim 3 , wherein the blank is shaped into a dental restoration by machining or pressing.5. The lithium silicate glass ceramic of claim 4 , wherein machining comprises grinding claim 4 , trimming or milling.6. The lithium silicate glass ceramic of claim 4 , wherein the dental restoration is an inlay claim 4 , an onlay claim 4 , a bridge claim 4 , an abutment claim 4 , a facing claim 4 , a veneer claim 4 , a facet claim 4 , a crown claim 4 , a partial crown claim 4 , a framework or a coping.7. The lithium silicate glass ceramic of claim 1 , comprising SiO claim 1 , LiO and a nucleating agent.8. A lithium silicate glass ceramic material formed by:{'sub': 2', '2', '2', '2', '3, 'a) heating a starting glass material which is essentially free of ZnO and comprises SiO, LiO, KO, AlO, nucleating agent, and optionally Me(II)O, wherein Me is CaO, BaO, MgO, SrO or combinations thereon, at a first temperature such that nuclei suitable to form lithium metasilicate crystals are formed; and'}b) heating the material from a) at a second temperature which is higher than the first temperature to produce lithium silicate glass ceramic which has lithium metasilicate as the main crystalline phase, and wherein the crystals are of ...
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