Patent ID: 8178012

Claim:
A method of forming a dental ceramic restorative article, the method comprising: providing a first uncolored powder, wherein the first uncolored powder comprises zirconia; combining at least one first coloring agent and a second powder thereby forming a first pigment powder, wherein the first coloring agent is a salt, oxide, inorganic compound, organic compound, organo-metallic compound or a combination thereof and wherein the second powder comprises zirconia; mixing the first uncolored powder and the first pigment powder, thereby forming a mixed powder; wherein an amount of the first coloring agent contained in the first pigment powder is selected, a proportion of first pigment powder and first uncolored powder in the mixed powder is selected, so as to provide the resulting dental restorative article with a tooth color having CIE L*, a*, b* color coordinates matching a shade standard within CIE L*, a*, b* color space region associated with tooth colors; shaping the mixed powder to form a shaped body; and firing the shaped body to at least 98% of its theoretical density; thereby producing a dental restorative article comprising a color corresponding to a predetermined natural tooth shade and a flexural strength of at least 800 MPa.