Lithium silicate materials

• US 8,444,756 B2
• Filed: 07/09/2010
• Issued: 05/21/2013
• Est. Priority Date: 08/07/2003
• Status: Active Grant

• Current Assignee: Ivoclar Vivadent AG
• Original Assignee: Ivoclar Vivadent AG
• Inventors: Schweiger, Marcel, Rheinberger, Volker, Burke, Harald, Holand, Wolfram, Apel, Elke, Ritzberger, Christian, Brodkin, Dmitri
• Primary Examiner(s): Koslow, Carol M
• Application Number:
  US12/833,721
• Publication Number:
  US 20110009254A1
• Time in Patent Office: 1,047 Days
• Field of Search: 501/5, 501/2, 501/154, 106/35, 428/428, 428/426, 428/699
• US Class Current: 106/35
• CPC Class Codes: A61C 13/0006 Production methods
• CPC Class Codes: A61C 13/0022 Blanks or green, unfinished dental restoration parts
• CPC Class Codes: A61C 13/083 Porcelain or ceramic teeth A61C13/081 takes precedence; preparations A61K6/80
• CPC Class Codes: A61C 13/09 Composite teeth, e.g. front and back section A61C13/0835, A61C13/1023 take precedence; Multilayer teeth
• CPC Class Codes: A61C 5/77 Methods or devices for making crowns
• CPC Class Codes: A61K 6/802 comprising ceramics
• CPC Class Codes: C03B 19/02 by casting molten glass, e.g. injection moulding
• CPC Class Codes: C03B 32/02 Thermal crystallisation, e.g. for crystallising glass bodies into glass-ceramic articles C03B27/012 takes precedence
• CPC Class Codes: C03C 10/0009 containing silica as main constituent
• CPC Class Codes: C03C 10/0027 containing SiO2, Al2O3, Li2O as main constituents
• CPC Class Codes: C03C 17/02 with glass C03C17/34, C03C17/44 take precedence
• CPC Class Codes: C03C 2217/92 Coating of crystal glass
• CPC Class Codes: C03C 3/097 containing phosphorus, niobium or tantalum
• CPC Class Codes: C03C 4/0021 for dental use

Abstract

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

Claims

1. A machinable lithium silicate dental glass-ceramic article comprising lithium metasilicate as the main crystalline phase and exhibiting a flexural strength of greater than 180 MPa.

2. The machinable lithium silicate dental glass-ceramic article of claim 1 wherein the flexural strength is in the range of about 190 to about 400 MPa.

3. The machinable lithium silicate dental glass-ceramic article of claim 1, wherein the fracture toughness is less than about 2.0 MPam^0.5.

4. The machinable lithium silicate dental glass-ceramic article of claim 1, wherein the fracture toughness is less than about 1.5 MPam^0.5.

5. The machinable lithium silicate dental glass-ceramic article of claim 1 wherein the glass ceramic comprises SiO₂, Li₂O and P₂O₅ or another nucleating agent.

6. The machinable lithium silicate dental glass-ceramic article of claim 1 wherein the machinable phase comprises lamellar or platelet crystals.

7. The machinable lithium silicate dental glass-ceramic article of claim 1 further comprising lithium disilicate.

8. The machinable lithium silicate dental glass-ceramic article of claim 1 machined into an inlay, an onlay, a bridge, an abutment, a facing, a veneer, a facet, a crown, a partial crown, a framework or a coping.

9. The machinable lithium silicate dental glass-ceramic article of claim 5 further comprising one or more of K₂O, Al₂O₃, ZnO, Na₂O, ZrO₂, Me^IIO, and a coloring/fluorescent metal oxide.

10. The machinable lithium silicate dental glass-ceramic article of claim 9 wherein the Me^IIO comprises CaO, BaO, SrO, MgO or a combination thereof.

11. The machinable lithium silicate dental glass-ceramic article of claim 9 wherein the coloring/fluorescent metal oxide comprises an oxide of Ta, Tb, Y, La, Er, Pr, Ce, Ti, V, Fe, Mn or a combination thereof.

12. The machinable lithium silicate dental glass-ceramic article of claim 1 further comprises a coating thereon.

13. The machinable lithium silicate dental ceramic article of claim 12 wherein the coating comprises glass or a glass ceramic.

14. The machinable lithium silicate dental glass-ceramic article of claim 12 wherein the coating comprises a stain and/or a glaze.

15. The lithium silicate dental glass-ceramic article of claim 1 wherein flexural strength comprises biaxial, 3-point bend or 4-point bend strength.