Lithium silicate materials

Patent metadata

Field	Value
Publication number	US-10214443-B2
Application number	US-201615255443-A
Country	US
Kind code	B2
Filing date	Sep 2, 2016
Priority date	Feb 8, 2005
Publication date	Feb 26, 2019
Grant date	Feb 26, 2019

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 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 thereof, at a first temperature of 500 to 600° C. such that nuclei suitable to form lithium metasilicate crystals are formed; and
b) heating the material formed after step a) at a second temperature of 680 to 720° C. to produce a 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.

2. The lithium silicate glass ceramic of claim 1 , wherein the glass ceramic is a dental product.

3. A lithium silicate glass ceramic material formed by:
a) heating a starting glass material which is essentially free of ZnO and comprises

Component
wt. %

SiO 2
64.0-75.0

LiO 2
13.0-17.0

K 2 O
2.0-5.0

Al 2 O 3
0.5-5.0

Nucleating agent
2.0-5.0

Me(II)O
0.0-3.0

wherein the optional Me(II)O is at least one of CaO, BaO, MgO, SrO or combinations thereof, at a first temperature of 500 to 600° C. such that nuclei suitable to form lithium metasilicate crystals are formed; and
b) heating the material from a) at a second temperature of 680 to 720° C. to produce a 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.

4. The lithium silicate glass ceramic material of claim 3 , wherein the starting glass material further comprises 0.1-4.0 wt. % ZrO 2 .

5. The lithium silicate glass ceramic material of claim 3 , wherein the process further comprises heating the material from b) at a third temperature of 830 to 880° C. to obtain a lithium silicate glass ceramic having lithium disilicate as the main crystalline phase.

Assignees

• Ivoclar Vivadent Ag

Inventors

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

Classifications

• A61K6/78

  Pigments · CPC title

• A61K6/807

  comprising magnesium oxide · CPC title

• A61K6/833

  Glass-ceramic composites · CPC title

• A61K6/804

  comprising manganese oxide · CPC title

• A61K6/818

  comprising zirconium oxide · CPC title