Lithium silicate diopside glass ceramics
AssigneeIvoclar Vivadent AG
InventorsMarkus Rampf, Christian Ritzberger, Marc Dittmer, Wolfram Höland, Marcel Schweiger
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Abstract
Lithium silicate-diopside glass ceramics are described which are characterized by a controllable translucence and can be satisfactorily processed mechanically and therefore can be used in particular as restoration material in dentistry.
Claims23
Lithium silicate-diopside glass ceramic which comprises 2.0 to 8.0 wt.-% P2O5 and comprises lithium silicate as main crystal phase and diopside as further crystal phase.
Starting glass which comprises the following components:
- Component
- wt.-%
- SiO2
- 53.0 to
- 75.0
- Li2O
- 10.0 to
- 23.0
- CaO
- 1.0 to
- 13.0
- MgO
- 1.0 to
- 12.0
- Al2O3
- 0.1 to
- 8.0
- P2O5
- 0 to
- 8.0
- MeI2O
- 0 to
- 10.0
- MeIIO
- 0 to
- 10.0
- MeIII2O3
- 0.1 to
- 10.0
- MeIVO2
- 0 to
- 15.0
- MeV2O5
- 0 to
- 4.0
- MeVIO3
- 0 to
- 5.0
- fluorine
- 0 to
- 3.0,
- wherein
- MeI2O is selected from Na2O, K2O, Rb2O and/or Cs2O,
- MeIIO is selected from SrO and/or ZnO,
- MeIII2O3 is selected from Al2O3, B2O3, Y2O3, La2O3, Ga2O3 and/or In2O3,
- MeIVO2 is selected from ZrO2, GeO2, CeO2, TiO2 and/or SnO2,
- MeV2O5 is selected from V2O5, Ta2O5 and/or Nb2Os, and
- MeVO3 is WO3 and/or MoO3, and
- comprises nuclei for the crystallization of lithium metasilicate or lithium disilicate as main crystal phase and diopside as further crystal phase.
Process for the preparation of a lithium silicate-diopside glass ceramic which comprises lithium silicate as main crystal phase and diopside as further crystal phase, wherein
- (a) a starting glass is ground,
- (b) the ground starting glass is optionally pressed to form a powder green compact and
- (c) the ground starting glass or the powder green compact is subjected to at least one heat treatment at a temperature in the range of from 500° to 1000° C. for a period of from 5 to 120 min.
Lithium silicate-diopside glass ceramic, which comprises 53.0 to 70.0 wt.-% SiO2 and comprises lithium silicate as main crystal phase and diopside as further crystal phase.
Lithium silicate-diopside glass ceramic, which comprises 0.5 to 10.0 wt.-% further alkali metal oxide MeI2O, wherein MeI2O is selected from Na2O, K2O, Rb2O and/or Cs2O and comprises lithium silicate as main crystal phase and diopside as further crystal phase.
Lithium silicate-diopside glass ceramic, which comprises 0.1 to 8.0 wt.-% Al2O3 and comprises lithium silicate as main crystal phase and diopside as further crystal phase.
Dependencies are inferred from the claim text.