Abstract: The invention relates to a process of producing a dental zirconia article, the process comprising the step of sintering a porous dental zirconia article, the sintering comprising a heat-treatment segment A characterized by a heating rate of at least 3 K/sec up to a temperature of at least 1,200° C., the porous dental zirconia article being composed of a zirconia material containing 6.0 to 8.0 wt. % yttria, 0.05 to 0.12 wt. % alumina and comprising a coloring component containing Tb, the porous dental zirconia article being essentially free of Fe components. The invention also relates to a process comprising the additional step of applying a glazing composition to the outer surface of the porous zirconia article before the heat-treatment or sintering is conducted.

Abstract: The invention relates to a process of sintering a dental zirconia restoration, the process comprising a first step of heat-treating a porous dental zirconia article with a heating rate of at least 3 K/sec until a temperature level of 75 to 90% of the final sintering temperature is achieved to obtain a partially sintered dental zirconia article, the porous dental zirconia article having a BET surface of 5 to 12 m2/g and being composed of a 4 mol % yttria stabilized zirconia material and having an alumina content of utmost 0.15 wt. %.

Abstract: The invention relates to a process of producing a dental zirconia restoration, the dental zirconia restoration having an outer and an inner surface, the process comprising the step of firing a porous dental zirconia restoration and a glass until the porous dental zirconia restoration is sintered, the glass being located during the firing step on at least a portion of the outer surface of the porous dental zirconia restoration, wherein the zirconia material of the porous dental zirconia restoration and the glass are selected such that during the firing step the glass infiltrates the pores of the porous dental zirconia restoration to an extent of not more than 5 ?m in depth. The invention also relates to a sintered dental zirconia restoration obtainable by such a process and a kit of parts comprising a porous dental zirconia mill blank and a surface treating agent containing a glass for use in such a process.

Abstract: The invention relates to a dental mill blank comprising a pre-sintered porous zirconia material, the porous pre-sintered zirconia material showing a N2 adsorption of isotherm type IV according to IUPAC classification, the porous pre-sintered zirconia material having a Vickers hardness from about 25 to about 150, the dental mill blank comprising means for reversible attaching it to a machining device. The invention also relates to a process of producing a zirconia dental article comprising the steps of providing a dental mill blank comprising a porous pre-sintered zirconia material, placing the dental mill blank in a machining device, machining the porous zirconia material and to a dental article obtained by such a process.

Abstract: The invention relates to a dental mill blank comprising a pre-sintered porous zirconia material, the porous pre-sintered zirconia material showing a N2 adsorption of isotherm type IV according to IUPAC classification, the porous pre-sintered zirconia material having a Vickers hardness from about 25 to about 150, the dental mill blank comprising means for reversible attaching it to a machining device. The invention also relates to a process of producing a zirconia dental article comprising the steps of providing a dental mill blank comprising a porous pre-sintered zirconia material, placing the dental mill blank in a machining device, machining the porous zirconia material and to a dental article obtained by such a process.