Methods for enhancing optical and strength properties in ceramic bodies having applications in dental restorations

Patent metadata

Field	Value
Publication number	US-10667992-B2
Application number	US-201815923565-A
Country	US
Kind code	B2
Filing date	Mar 16, 2018
Priority date	Mar 16, 2017
Publication date	Jun 2, 2020
Grant date	Jun 2, 2020

Abstract

A method for enhancing optical properties of sintered, zirconia ceramic bodies and zirconia ceramic dental restorations is provided. The porous or pre-sintered stage of a ceramic body is treated with two different yttrium-containing compositions and sintered, resulting in sintered ceramic bodies having enhanced optical properties. The enhanced optical properties may be substantially permanent, remaining for the useful life of the sintered ceramic body.

First claim

We claim:

1. A method of enhancing optical properties in a dental restoration comprising
obtaining a porous zirconia ceramic body in the shape of a dental restoration comprising a facial surface having an incisal edge and an incisal region, that comprises an yttria-stabilized zirconia material comprising 2 mol % yttria to 7 mol % yttria;
obtaining a first aqueous yttrium-containing composition comprising
between 5 wt % and 35 wt % of a first yttrium-containing material based on the total weight of the first aqueous yttrium-containing composition, and
a first colorant comprising at least one metal-containing component as a coloring agent;

obtaining a second aqueous yttrium-containing composition comprising
between 20 wt % and 70 wt % of a second yttrium-containing material based on the total weight of the second aqueous yttrium-containing composition,
wherein the weight percent of yttrium-containing material in the second composition is greater than in the first aqueous yttrium-containing composition,
wherein the first and second yttrium-containing materials may be the same or different, and
optionally, a second colorant comprising at least one metal-containing component as a coloring agent,

applying the first aqueous yttrium-containing composition to penetrate at least a portion of the porous zirconia ceramic body that extends from the incisal edge to a distance of one third to two thirds the dental restoration length measured from the incisal edge to a margin of the dental restoration;
applying the second aqueous yttrium-containing composition to penetrate at least a portion of the incisal region; and
sintering the porous zirconia ceramic body after applying the first and second aqueous yttrium-containing compositions to form a dental restoration.

2. The method of claim 1 , comprising applying the first aqueous yttrium-containing composition to a cavity surface to penetrate the porous zirconia ceramic body.

3. The method of claim 1 , wherein the second aqueous yttrium-containing composition is applied from the incisal edge to a distance of 1 mm to 5 mm from the incisal edge.

4. The method of claim 1 , wherein the second aqueous yttrium-containing composition is applied from the incisal edge to a distance of 0.5 mm to 3 mm from the incisal edge.

5. The method of claim 3 , further comprising a second application of the second aqueous yttrium-containing composition that is applied from the incisal edge to a distance of 0.5 mm to 2 mm from the incisal edge, wherein the distance of the second application is less than the first application of the second aqueous yttrium-containing composition.

6. The method of claim 1 , wherein the first aqueous yttrium-containing composition comprises between 10 wt % and 20 wt % yttrium chloride.

7. The method of claim 1 , wherein the second aqueous yttrium-containing composition comprises between 45 wt % and 70 wt % yttrium-containing composition and citric acid as a solubilizing agent.

8. The method of claim 1 , wherein the first aqueous yttrium-containing composition comprises between 5 wt % and 15 wt % yttrium-containing material and the second aqueous yttrium-containing composition comprises between 40 wt % and 65 wt % yttrium-containing material.

9. The method of claim 1 , wherein the at least one metal-containing component of the first aqueous yttrium-containing composition comprises at least one metal selected from terbium, chromium, and manganese, as a coloring agent.

10. The method of claim 1 , wherein, the second colorant comprise a copper-containing component or a cobalt-containing component.

11. The method of claim 1 , wherein the second colorant comprises from 0.005 wt % to 0.3 wt % of a cobalt salt.

12. The method of claim 1 , wherein the yttria-stabilized zirconia material comprises 2 mol % yttria 5 mol % yttria.

13. The method of claim 1 , wherein the porous zirconia ceramic body is formed from a shaded zirconia ceramic material.

14. A method for enhancing optical properties of a dental restoration comprising
obtaining a porous zirconia ceramic body in the shape of a dental restoration comprising a facial surface between an incisal edge and a margin, an incisal region adjacent the incisal edge, a cervical region adjacent the margin, and a middle region between the incisal region and the cervical region,
wherein the porous zirconia ceramic body comprises an yttria-stabilized zirconia material comprising 2 mol % yttria to 7 mol % yttria;
obtaining a first aqueous yttrium-containing composition comprising
between 5 wt % and 35 wt % of a first yttrium-containing material based on the total weight of the first aqueous yttrium-containing composition, and
a first colorant comprising at least one metal-containing component as a coloring agent;

obtaining a second aqueous yttrium-containing composition comprising
between 20 wt % and 70 wt % of a second yttrium-containing material based on the total weight of the second aqueous yttrium-containing composition, and
optionally, a second colorant comprising at least one metal-containing component as a coloring agent,

 wherein the weight percent of yttrium-containing material in the second composition is greater than in the first aqueous yttrium-containing composition, and
 wherein the first yttrium-containing material and the second yttrium-containing material are the same or different; and
applying the first aqueous yttrium-containing composition to the porous zirconia ceramic body to penetrate at least a portion of the incisal region, and optionally, at least a portion of the middle region; and
applying the second aqueous yttrium-containing composition to penetrate at least a portion of the incisal region.

15. The method of claim 14 , wherein the first aqueous yttrium-containing composition comprises yttrium (III) chloride hexahydrate.

16. The method of claim 14 , wherein the first aqueous yttrium-containing composition and the second aqueous yttrium-containing composition comprise yttrium (III) chloride hexahydrate.

17. The method of claim 14 , comprising applying the second aqueous yttrium-containing composition to a portion of the facial surface comprising the first aqueous yttrium-containing composition, wherein the distance of the second aqueous yttrium-containing composition from the incisal edge toward the margin is less than the first aqueous yttrium-containing composition.

18. The method of claim 17 , comprising applying the second aqueous yttrium-containing composition from the incisal edge toward the margin for a distance of 0.5 mm to 3 mm from the incisal edge.

19. The method of claim 17 , comprising applying a second application of the second aqueous yttrium-containing composition, wherein the distance of the second application from the incisal edge toward the margin is less than the first application of the second aqueous yttrium-containing composition.

20. The method of claim 14 , wherein the first aqueous yttrium-containing composition comprises between 5 wt % and 35 wt % of a yttrium salt in an aqueous solution and the second aqueous yttrium-containing composition comprises between 40 wt % and 70 wt % of a yttrium salt in an aqueous solution.

21. The method of claim 14 , wherein the first yttrium-containing material comprises 5 wt % and 20 wt % of a yttrium salt in an aqueous solution.

22. The method of claim 14 , wherein the second yttrium-containing material comprises between 50 wt % and 70 wt % of a yttrium salt in an aqueous solution.

Assignees

• Glidewell James R Dental Ceramics Inc

Inventors

• Kim Jae Won
• Akash

Classifications

• C04B41/0072

  Heat treatment · CPC title

• C04B2103/54

  Pigments; Dyes · CPC title

• C04B41/4572

  Partial coating or impregnation of the surface of the substrate · CPC title

• B05D1/28

  performed by transfer from the surfaces of elements carrying the liquid or other fluent material, e.g. brushes, pads, rollers · CPC title

• C04B41/4574

  Coating different parts of the substrate with different materials · CPC title