Method for coloring ceramics via colloidal dispersion

A method of coloring a dental ceramic product that is fabricated using a colloidal mixing process to form a slurry which can be slip cast into preformed molds, then dried and sintered;

• the method comprising the steps of:
• a) forming a coloring solution consisting essentially of at least one metallic salt, a solvent, an organic solvent and an acid, wherein the metallic salts comprise 0.01% to 5% by weight of the coloring solution and the coloring solution comprises TbC13 and CrC13;
• b) choosing the relative constituents of the coloring solution to provide a selected color;
• c) choosing a relative amount of the coloring solution for an amount of a slurry to provide a selected color intensity;
• d) adding the relative amount of the coloring solution to the amount of a slurry;
• and
• e) mixing the slurry and coloring solution to homogeneously distribute the coloring solution throughout the slurry.

A method of forming zirconia dental ceramic product comprising;

• a) forming a coloring solution consisting essentially of water, 0.01% to 5% by weight of at least one metallic salt by weight of the coloring solution having anions selected from the group consisting of Cl−, SO42−, SO3−, Br−, F−, NO2−, and NO3−, optionally an organic solvent, and optionally, an acid to provide a pH of 1.0 to 4.0 for the coloring solution;
• b) choosing a relative amount of the coloring solution for an amount of a zirconia ceramic slurry to provide a selected color intensity;
• c) adding the relative amount of coloring solution to the amount of zirconia ceramic slurry;
• and
• d) mixing to homogeneously distribute the coloring solution throughout the zirconia ceramic slurry;
• and
• e) slip-casting the slurry into preformed molds forming homogeneously colored ceramic bodies made predominantly of zirconia.