Lithium silicate materials

Patent metadata

Field	Value
Publication number	US-10136973-B2
Application number	US-201514984490-A
Country	US
Kind code	B2
Filing date	Dec 30, 2015
Priority date	Aug 7, 2003
Publication date	Nov 27, 2018
Grant date	Nov 27, 2018

Abstract

Lithium silicate materials are described which can be easily processed by machining to dental products without undue wear of the tools.

First claim

The invention claimed is:

1. A process for manufacturing a lithium silicate dental glass-ceramic article comprising: preparing a lithium silicate blank comprising lithium metasilicate as the main crystalline phase and exhibiting a flexural strength of greater than 180 MPa; machining the lithium silicate blank into a dental article; and heat treating the machined dental article in the temperature range of from about 700° C. to about 900° C. to close surface flaws, and optionally, coating with a glass or glass ceramic by sintering or hot pressing.

2. A process for manufacturing a lithium silicate dental glass-ceramic article comprising: preparing a lithium silicate blank comprising lithium metasilicate as the main crystalline phase and exhibiting a flexural strength of greater than 180 MPa; machining the lithium silicate blank into a dental article; and applying a coating thereon, wherein the coating is applied by sintering or pressing and the coating comprises glass or a glass ceramic.

3. A process for the preparation of a lithium silicate blank, which comprises:
producing a melt of a starting glass containing the initial components 64.0-73.0% by weight SiO 2 , 13.0-17.0% by weight Li 2 O, 2.0-5.0% by weight K 2 O, 0.5-5.0% by weight Al 2 O 3 and 2.0-5.0% by weight P 2 O 5 or other nucleation agent as the main components,
pouring the melt of the starting glass into a mold to form a starting glass blank,
subjecting the starting glass blank to heat treatment to obtain the lithium silicate blank with lithium metasilicate crystals as the main crystalline phase by heating the glass blank to a temperature in the range from about 450° C. to about 700° C. for a time between about 5 minutes and about 1 hour, and
cooling the lithium silicate blank having the lithium metasilicate crystals as the main crystalline phase.

4. A process for manufacturing a lithium silicate dental glass-ceramic article comprising: preparing a lithium silicate blank comprising lithium metasilicate as the main crystalline phase and exhibiting a flexural strength of greater than 180 MPa; machining the lithium silicate blank into a dental article; and further finishing the dental article by staining, glazing, or veneering the dental glass-ceramic with an overlay porcelain and firing in the temperature range of from about 350° C. to about 850° C.

Assignees

• Ivoclar Vivadent Ag

Inventors

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

Classifications

• A61K6/802

  comprising ceramics · CPC title

• A61C13/09

  {Composite teeth, e.g. front and back section (A61C13/0835, A61C13/1023 take precedence)}; Multilayer teeth · CPC title

• A61C13/0006

  Production methods · CPC title

• C03C4/0021

  for dental use · CPC title

• C03C10/0027

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