Process for producing a colored dental zirconia article

A process of producing a colored dental zirconia article, the process comprising:

• providing a porous dental zirconia article, the porous dental zirconia article comprising a zirconia material containing 6.0 to 8.0 wt. % yttria, 0.05 to 0.12 wt. % alumina, and a coloring component containing Tb in an amount of 0.005 to 0.70 wt. % with respect to the porous dental zirconia article calculated on the amount of Tb4O7, the coloring component being uniformly distributed within the zirconia material,
• applying a glazing composition to an outer surface of the porous dental zirconia article before conducting a heat-treatment segment A, the glazing composition comprising a silica-based glass having at least 80 mol % SiO2, wherein the amounts are given in mol % with respect to the silica-based glass;
• sintering the porous dental zirconia article, the sintering comprising:
• the heat-treatment segment A with a heating rate of at least 3 K/sec up to a temperature of at least 1,200° C., and
• a heat-treatment segment B with a heating rate that is lower than the heating rate of heat-treatment segment A and is conducted after the heat-treatment segment A for a duration of no more than 10 minutes, up to a temperature of at least 1,300° C.,
• wherein the porous dental zirconia article is essentially free of Fe components.