Method for producing a blank, blank and a dental restoration

Patent metadata

Field	Value
Publication number	US-11464608-B2
Application number	US-201916595556-A
Country	US
Kind code	B2
Filing date	Oct 8, 2019
Priority date	Dec 28, 2015
Publication date	Oct 11, 2022
Grant date	Oct 11, 2022

Abstract

The invention relates to a blank of a ceramic material, wherein a first ceramic material and then a second ceramic material of different compositions are filled into a die and wherein the materials are pressed and after pressing are sintered. A layer of the first ceramic material is thereby filled into the die and a first cavity formed in the layer, the second ceramic material is then filled into the first open cavity and the materials pressed together and then heat-treated.

First claim

The invention claimed is:

1. A pre-sintered or fully-sintered blank for use in preparing a dental restoration, the blank having regions of different compositions, wherein the blank comprises one first region of a first ceramic material and at least one second region of a second ceramic material, the first region and the at least one second region being of different compositions and are sited next to one another, wherein the first and second ceramic materials include zirconium dioxide doped with yttrium oxide (Y2O3), and optionally calcium oxide (CaO), magnesium oxide (MgO) and/or ceroxide (CeO2), and wherein the first ceramic material differs from the material of the second ceramic material in terms of color and proportions of stabilized crystal forms present at room temperature, and wherein the at least one second region extends within the first region and has an external geometry that tapers from a base region or a base surface and wherein percentage of yttrium oxide in the second ceramic material lies between 4.5 wt % and 7.0 wt % and in the first ceramic material between 7.0 wt % and 9.5 wt %, wherein the percentage of yttrium oxide in the first ceramic material is greater than in the second ceramic material and wherein the first region of the first ceramic material has a tetragonal crystal phase ranging from 50%-60%.

2. The blank according to claim 1 , wherein the base region or the base surface of the at least one second region extends in the region of an outer surface of the first region.

3. The blank according to claim 1 , wherein the at least one second region starting from its base region or base surface has a cavity.

4. The blank according to claim 1 , wherein the at least one second region has a conus-like geometry on its outer side.

5. The blank according of claim 1 , wherein the at least one second region includes a third region extending at least partially therein, the third region including a third ceramic material having a composition different from that of the first and/or second ceramic material.

6. The blank according to claim 1 , wherein the composition of the third ceramic material includes zirconium dioxide to which yttrium oxide has been added.

7. The blank according to claim 6 , wherein the thermal expansion coefficient of the first region is 0.2 μm/m*K to 0.8 μm/m*K lower than the thermal expansion coefficient of the at least one second and/or third regions.

8. The blank according to claim 1 , wherein the at least one second region includes a plurality of second regions surrounded by the first region.

9. The blank according to claim 8 , wherein at least some of the plurality of second regions differ from one another in their external geometries.

10. The blank according to claim 1 , wherein the second ceramic material differs from the first ceramic material in being colored.

11. The blank according to claim 1 , wherein after full sintering the restoration produced from the blank has a higher strength on a dentine side than on an incisal side and/or on the incisal side has a higher translucency than on the dentine side.

12. A dental restoration prepared from a blank according to claim 1 , wherein the restoration is formed monolithically and comprises at least one first layer extending on an incisal side of a first ceramic material and a second layer extending on an dentine side of a second ceramic material, wherein the first layer has a higher translucency and/or lower strength than the second layer, and wherein the ceramic materials include zirconium dioxide doped with yttrium oxide (Y2O3), and optionally calcium oxide (CaO), magnesium oxide (MgO) and/or ceroxide (CeO2), and wherein the first ceramic material differs from the material of the second ceramic material in terms of color and proportions of stabilized crystal forms present at room temperature, and wherein percentage of yttrium oxide in the second ceramic material lies between 4.5 wt % and 7.0 wt % and in the first ceramic material between 7.0 wt % and 9.5 wt %, wherein the percentage of yttrium oxide in the first ceramic material is greater than in the second ceramic material.

13. The dental restoration according to claim 12 , wherein the thermal expansion coefficient of the first layer is 0.2 μm/m*K to 0.8 μm/m*K lower than the thermal expansion coefficient of the second layer.

Assignees

• Dentsply Sirona Inc

Inventors

• Volkl Lothar
• Kutzner Martin
• Oefner Tanja
• Fecher Stefan

Classifications

• A61C13/082

  Cosmetic aspects, e.g. inlays; Determination of the colour (A61C19/10 takes precedence) · CPC title

• C04B2235/3281

  Copper oxides, cuprates or oxide-forming salts thereof, e.g. CuO or Cu2O · CPC title

• C04B2235/765

  Tetragonal symmetry · CPC title

• A61C5/73

  Composite crowns · CPC title

• A61C13/083

  Porcelain or ceramic teeth {(A61C13/081 takes precedence; preparations A61K6/80)} · CPC title