Lithium silicate materials
AssigneeIvoclar Vivadent AG
InventorsElke Signer-Apel, Wolfram Höland, Marcel Schweiger, Christian Ritzberger, Harald Bürke, Volker Rheinberger
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Abstract
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.
Claims9
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, and wherein the molar ratio of SiO2 to Li2O is at least 2.2:1.
A lithium silicate glass ceramic material formed by:
- a) heating a starting glass material which is essentially free of ZnO and comprises SiO2, LiO2, K2O, Al2O3, nucleating agent, and optionally Me(II)O, wherein Me(II)O is CaO, BaO, MgO, SrO or combinations thereon, in a first temperature range for a period of time such that nuclei suitable to form lithium metasilicate crystals are formed;
- and
- b) heating the material from a) in a second temperature range, which is higher than the first temperature range for a period of time to produce lithium silicate glass ceramic which has lithium metasilicate as the main crystalline phase, and wherein the crystals are of lamellar or platelet form.
Dependencies are inferred from the claim text.