Pre-sintered blank for dental purposes

Patent metadata

Field	Value
Publication number	US-10470854-B2
Application number	US-201314400383-A
Country	US
Kind code	B2
Filing date	May 10, 2013
Priority date	May 11, 2012
Publication date	Nov 12, 2019
Grant date	Nov 12, 2019

Abstract

Pre-sintered blanks based on lithium disilicate glass ceramic are described which are suitable in particular for the preparation of dental restorations.

First claim

The invention claimed is:

1. Pre-sintered blank for dental purposes based on lithium disilicate glass ceramic, wherein the blank has a relative density of from 60 to 90%, relative to the true density of the glass ceramic, and wherein the blank has a relative density which results when
(a) powder of a corresponding starting glass with an average particle size of <100 μm, relative to the number of particles, is uniaxially or isostatically pressed at a pressure of from 20 MPa to 200 MPa and
(b) the obtained glass powder green compact is heat-treated for 2 to 120 min at a temperature
(i) which temperature is at least 500° C., and
(ii) which temperature lies in a temperature range which extends over at least 30° C. and in which temperature range the relative density varies by less than 2.5%.

2. Pre-sintered blank according to claim 1 , which consists essentially of lithium disilicate glass ceramic.

3. Pre-sintered blank according to claim 1 , wherein the glass ceramic includes lithium disilicate as main crystal phase.

4. Pre-sintered blank according to claim 3 , wherein the glass ceramic contains more than 10 vol.-% lithium disilicate crystals.

5. Pre-sintered blank according to claim 3 , wherein the glass ceramic contains more than 20 vol.-% lithium disilicate crystals.

6. Pre-sintered blank according to claim 1 , wherein the lithium disilicate glass ceramic contains at least one of the following components:

Component
wt. %

SiO 2
50.0 to 80.0

Li 2 O
 6.0 to 20.0

Me(I) 2 O
  0 to 10.0

Me(II)O
  0 to 12.0

Me(III) 2 O 3
  0 to 8.0

Me(IV)O 2
  0 to 8.0

Me(V) 2 O 5
  0 to 8.0

Me(VI)O 3
  0 to 8.0

nucleating agent
   0 to 8.0,

wherein
Me(I) 2 O is selected from Na 2 O, K 2 O, Rb 2 O, Cs 2 O or mixtures thereof,
Me(II)O is selected from CaO, BaO, MgO, SrO, ZnO and mixtures thereof,
Me(III) 2 O 3 is selected from Al 2 O 3 , La 2 O 3 , Bi 2 O 3 , Y 2 O 3 , Yb 2 O 3 and mixtures thereof,
Me(IV)O 2 is selected from ZrO 2 , TiO 2 , SnO 2 , GeO 2 and mixtures thereof,
Me(V) 2 O 5 is selected from Ta 2 O 5 , Nb 2 O 5 and mixtures thereof,
Me(VI)O 3 is selected from WO 3 , MoO 3 and mixtures thereof, and
nucleating agent is selected from P 2 O 5 , metals and mixtures thereof.

7. Pre-sintered blank according to claim 1 , which has at least two areas which differ by their coloration or translucence.

8. Pre-sintered blank according to claim 7 , which has at least two layers which differ by their coloration or translucence.

9. Pre-sintered blank according to claim 1 , which has a holder for securing the blank to a processing device.

10. Pre-sintered blank according to claim 1 , which has an interface for connection to a dental implant.

11. Pre-sintered blank according to claim 10 , wherein the interface comprises a recess for connection to the dental implant.

12. Pre-sintered blank according to claim 1 , wherein the blank has a relative density of from 62 to 88%, relative to the true density of the glass ceramic.

13. Pre-sintered blank according to claim 1 , wherein the blank has a relative density of from 65 to 87%, relative to the true density of the glass ceramic.

14. Pre-sintered blank according to claim 1 , wherein the lithium disilicate glass ceramic contains at least one of the following components:

Component
wt. %

SiO 2
50.0 to 80.0

Li 2 O
 6.0 to 20.0

Me(I) 2 O
 0.1 to 10.0

Me(II)O
 0.1 to 12.0

Me(III) 2 O 3
0.1 to 8.0

Me(IV)O 2
0.1 to 8.0

Me(V) 2 O 5
0.1 to 8.0

Me(VI)O 3
0.1 to 8.0

nucleating agent
 0.1 to 8.0,

wherein
Me(I) 2 O is selected from Na 2 O, K 2 O, Rb 2 O, Cs 2 O or mixtures thereof,
Me(II)O is selected from CaO, BaO, MgO, SrO, ZnO and mixtures thereof,
Me(III) 2 O 3 is selected from Al 2 O 3 , La 2 O 3 , Bi 2 O 3 , Y 2 O 3 , Yb 2 O 3 and mixtures thereof,
Me(IV)O 2 is selected from ZrO 2 , TiO 2 , SnO 2 , GeO 2 and mixtures thereof,
Me(V) 2 O 5 is selected from Ta 2 O 5 , Nb 2 O 5 and mixtures thereof,
Me(VI)O 3 is selected from WO 3 , MoO 3 and mixtures thereof, and
nucleating agent is selected from P 2 O 5 , metals and mixtures thereof.

15. Pre-sintered blank according to claim 1 , which has a relative density which results when
(a) powder of a corresponding starting glass with an average particle size of <100 μm, relative to the number of particles, is uniaxially or isostatically pressed at a pressure of from 40 to 120 MPa and
(b) the obtained glass powder green compact is heat-treated for 5 to 60 min at a temperature
(i) which temperature is at least 540° C., and
(ii) which temperature lies in a temperature range which extends over at least 50° C. and in which temperature range the relative density varies by less than 2.0%.

16. Pre-sintered bl

Assignees

• Ivoclar Vivadent Ag

Inventors

• Bürke Harald
• Ritzberger Christian
• Schweiger Marcel
• Rheinberger Volker

Classifications

• A61K6/827 Primary

  Leucite · CPC title

• C03B32/02

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

• C03C4/0021

  for dental use · CPC title

• C03C10/0027

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

• C03C10/0054

  containing PbO, SnO2, B2O3 · CPC title