A method of making a translucent colored zirconia dental restoration comprises obtaining a zirconia green body, forming a dental restoration precursor from the zirconia green body, applying a color liquid to the precursor, and sintering the restoration precursor with regular sintering in air without post HIP processing. The zirconia green body comprises between 7 wt % to 20 wt % of stabilizer based on a total weight percent of the zirconia green body, and at least some particles with a diameter of 100 nanometers to 1000 nanometers. The zirconia green body is subsequently finally sinterable with regular sintering in air without post HIP processing to produce a translucent zirconia sintered body having a total light transmittance of at least 36% and less than 50% to light with a wavelength of 400 nm, and less than 55% to light with a wavelength of 600 nm, at a thickness of 0.6 mm.

A method of making a translucent colored zirconia dental restoration comprises obtaining a zirconia green body, forming a dental restoration precursor from the zirconia green body, applying a color liquid to the precursor, and sintering the restoration precursor with regular sintering in air without post HIP processing. The zirconia green body comprises between 7 wt % to 20 wt % of stabilizer based on a total weight percent, and an L* value between 10 and 20 for a sample thickness of 1 to 1.3 mm. The zirconia green body is subsequently finally sinterable with regular sintering in air without post HIP processing to produce a translucent zirconia sintered body having a total light transmittance of at least 36% and less than 50% to light with a wavelength of 400 nm, and less than 55% to light with a wavelength of 600 nm, at a thickness of 0.6 mm.

A zirconia composition, a zirconia semi-sintered body, a zirconia sintered body, and a dental product are provided. The zirconia sintered body contains 4 mol % to 7 mol % of yttria as stabilizer, and a shielding material. The zirconia sintered body comprises first region and second region having a higher content ratio of the shielding material than the first region. Difference between content ratio of yttria in the first region and that of yttria in the second region is 1 mol % or less.

There is provided at least any of a layered body which has a change in color tone and in which it is unnecessary to select a colorant and the content of the colorant in consideration of a difference in the sintering behavior between layers, a precursor thereof, or a method for producing these. Provided is a layered body which has a structure, in which two or more layers containing stabilizer-containing zirconia and a colorant are layered, and in which types and contents of the colorants contained in the layers are equal to each other, the layered body including at least: a first layer containing a colorant and zirconia which has a stabilizer content of higher than or equal to 3.3 mol %; and a second layer containing a colorant and zirconia which has a stabilizer content different from that of the zirconia contained in the first layer.

Provided are a black mixed oxide that contains chromium per se of any valency as a main component, and fails to contain cobalt as the main component material, and has a high safety, an excellent color tone and economical efficiency, and a method for producing the same, and various products using the black mixed oxide material. The mixed oxides comprise oxides containing La, Mn and Cu as main components but containing neither Cr nor Co as a main component, wherein the contents of La, Mn and Cu in the mixed oxides satisfy the following ratios, as oxide equivalent amount with respect to 100% by weight of the oxide equivalent amount: the La content as La.sub.2O.sub.3 being 35-70 wt %; the Mn content as MnO.sub.2 being 25-60 wt %; and the Cu content as CuO being 0.5-10 wt %.

A zirconia sintered body comprising 3.0 wt % or more and 30.0 wt % or less of aluminum in terms of Al.sub.2O.sub.3 and a remainder is zirconia containing 2 mol % or more and 4 mol % or less of erbia, in which the zirconia sintered body includes grains of aluminum oxide, and a total light transmittance with respect to a D65 light source at a sample thickness of 1.0 mm is 10% or less.

A black zirconia sintered body is obtained by processing and forming a powder for the black zirconia sintered body, and then sintering the same at a high temperature and normal pressure in the atmosphere. The powder for the black zirconia sintered body is prepared by a hydrothermal synthesis method using a soluble zirconium salt, a soluble yttrium salt and a color former as raw materials, wherein the molar ratio of the soluble zirconium salt, the soluble yttrium salt and the color former is 90-95:1-5:1-9. The black zirconia sintered body can be used in ceramic processes.

Fused, monolithic 3-D products of high-SiO2-containing body materials, called FHD/S, cut to pattern, mating surfaces honed or polished, assembled with mating surfaces in contact, and fusion fired until the contacting parts fuse without added flux. Fused FHD/S products may be used unglazed, or glaze may be applied to selected fused surfaces and then glaze fired. FHD/S body materials may include colorants so that the fused parts exhibit color contrast and variation when used without glazing. Examples include countertops having integral fused vertical back-splashes and front edges, and bowls fused to openings. The inventive 3-D monolithic fused FHD/S products are produced in standard sizes or as custom-fit interior and exterior products that are stain resistant, moisture impervious, UV resistant, acid resistant, dimensionally stable, abrasion and impact resistant, and may be glazed to produce unique decorative and utilitarian surfaces in a wide range of colors and textures, including artistic, one-of-a-kind 3-D works.

Zirconia dental ceramics exhibiting opalescence and having a grain size in the range of 10 nm to 300 nm, a density of at least 99.5% of theoretical density, a visible light transmittance at or higher than 45% at 560 nm, and a strength of at least 800 MPa.

The present invention relates to a kit of parts comprising a dental mill blank comprising a porous zirconia material and a colouring solution for colouring the porous zirconia material. The porous zirconia material comprises Zr oxide calculated as ZrO2: from 80 to 97 wt.-%, Al oxide calculated as Al2O3: from 0 to 0.15 wt.-%, Y oxide calculated as Y2O3: from 1 to 10 wt.-%, Bi oxide calculated as Bi2O3: from 0.01 to 0.2 wt.-%, the porous zirconia material not comprising Fe calculated as Fe2O3 in an amount of more than 0.01 wt.-%, wt.-% with respect to the weight of the porous zirconia material. The colouring solution comprises solvent(s), colouring agent(s) comprising metal ions selected from Tb, Er, Pr, Mn or combinations thereof, the solution not comprising Fe ions in an amount of more than 0.01 wt.-%, the solution not comprising Bi ions in an amount of more than 0.01 wt.-%, wt.-% with respect to the weight of the colouring solution. The invention also relates to a process of producing a dental restoration, the process comprising the steps: providing a dental mill blank comprising a porous zirconia material as described in any of the preceding claims, machining an article out of the porous zirconia material, the article having the shape of a dental restoration with an outer and inner surface, providing a colouring solution as described in any of the preceding claims, applying the colouring solution to at least portions of the surface of the article having the shape of a dental restoration.