Lithium silicate materials

Patent metadata

Field	Value
Publication number	US-2020024181-A1
Application number	US-201916284563-A
Country	US
Kind code	A1
Filing date	Feb 25, 2019
Priority date	Feb 8, 2005
Publication date	Jan 23, 2020
Grant date	—

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.

First claim

What is claimed:

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, trimming or milling.

6 . The lithium silicate glass ceramic of claim 4 , wherein the dental restoration is an inlay, an onlay, a bridge, an abutment, a facing, a veneer, a facet, a crown, a partial crown, a framework or a coping.

7 . The lithium silicate glass ceramic of claim 1 , comprising SiO 2 , Li 2 O and a nucleating agent.

8 . A lithium silicate glass ceramic material formed by:
a) heating a starting glass material which is essentially free of ZnO and comprises SiO 2 , LiO 2 , K 2 O, Al 2 O 3 , 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 lamellar or platelet form, wherein the material formed after step b) is convertible to a lithium silicate glass ceramic having disilicate as the main crystalline phase by heating to a third temperature which is higher than the second temperature.

Assignees

• Ivoclar Vivadent Ag

Inventors

• Signer-Apel Elke
• Höland Wolfram
• Schweiger Marcel
• Ritzberger Christian
• Bürke Harald
• Rheinberger Volker

Classifications

• A61C13/082

  Cosmetic aspects, e.g. inlays; Determination of the colour (A61C19/10 takes precedence) · CPC title

• C03C10/0027 Primary

  containing SiO2, Al2O3, Li2O as main constituents · CPC title

• C03B32/02

  Thermal crystallisation, e.g. for crystallising glass bodies into glass-ceramic articles {(C03B27/012 takes precedence)} · CPC title

• A61K6/818

  comprising zirconium oxide · CPC title

• A61C8/0012

  characterised by the material or composition, e.g. ceramics, surface layer, metal alloy (use of specific materials A61K6/00) · CPC title