Method of masking a dental support structure of a dental prosthesis made of highly translucent ceramic material

Patent metadata

Field	Value
Publication number	US-12005131-B2
Application number	US-202117166942-A
Country	US
Kind code	B2
Filing date	Feb 3, 2021
Priority date	Feb 3, 2020
Publication date	Jun 11, 2024
Grant date	Jun 11, 2024

Abstract

A method for masking the appearance of a support structure underlying a highly translucent ceramic dental restoration is provided. The porous form of a zirconia ceramic dental restoration is treated with a liquid masking composition comprising 0.4 wt % to 50 wt % of one or more masking agents. The masking composition is applied to the internal surface of a restoration and a region of the facial surface of the restoration that is opposite the internal surface. After application of the masking compositions, treated zirconia restoration is sintered to greater than 98% theoretical density.

First claim

We claim:

1. A method for masking a dental substructure through a highly translucent yttria-stabilized zirconia dental restoration, comprising:
i. obtaining a masking mixture comprising 0.4 wt % to 50 wt % of one or more masking components that comprise Zn, Ti, Al, La, Mg, Sc, Si, Sr or Ca;
ii. obtaining a porous ceramic body in the shape of a dental restoration comprising an internal surface and a facial surface comprising an overlying region opposite the internal surface and wherein the ceramic body comprises zirconia stabilized with 3 mol % yttria to 8 mol % yttria having a transmittance between 45% to 80% at 700 nm (when tested on a 1 mm thick sintered body);
iii. applying the masking mixture to the internal surface to form an inner masking surface to mask a substructure;
iv. applying the masking mixture to the overlying region opposite the inner masking surface to form an outer masking surface; and
v. sintering the porous ceramic body to obtain a fully sintered ceramic body having a density that is at least 98% of the theoretical density, wherein the fully sintered ceramic body has a perceptual lightness (L*) value of at least 75 at a location that is on a centerline of the overlying region of the ceramic body and that is 69% of a distance from an incisal edge toward a gingival margin, and wherein perceptual lightness is measured using a SpectroShade® Micro II spectrophotometer.

2. The method of claim 1 , wherein the masking mixture comprises one or more masking components that comprise Zn or Al.

3. The method of claim 2 , wherein the masking mixture comprises one or more of zinc sulfate, zinc nitrate, or aluminum chloride.

4. The method of claim 1 , wherein the dental restoration comprises a veneer, a crown, a bridge, an implant-supported partial denture, or an implant-supported full-arch denture.

5. The method of claim 1 , wherein the fully sintered ceramic body has a Measured Lightness Slope Value (MLSV) that is between 7 and 22, wherein perceptual lightness (L*) is measured using a SpectroShade® Micro II spectrophotometer.

6. The method of claim 1 , wherein the fully sintered ceramic body has a Measured Lightness Slope Value (MLSV) that is between 9 and 17, wherein perceptual lightness (L*) is measured using a SpectroShade® Micro II spectrophotometer.

Assignees

• Glidewell James R Dental Ceramics Inc

Inventors

• Yang Yan
• Balasubramanian Sreeram
• Park Yang Soon

Classifications

• A61K6/15

  Compositions characterised by their physical properties · CPC title

• C04B2235/3246

  Stabilised zirconias, e.g. YSZ or cerium stabilised zirconia · CPC title

• C04B35/6303

  Inorganic additives · CPC title

• C04B2235/9661

  Colour · CPC title

• A61K6/84

  comprising metals or alloys · CPC title