Shaded Zirconium Oxide Articles

Abstract

A dental article includes yttria stabilized tetragonal zirconia polycrystalline ceramic, and no more than about 0.15 wt. % of one or more coloring agents of one or more of: Fe, Er, Co, Pr, Tb, Cr, Nd, Ce, V, Eu, Ho, Ni, and Cu, oxides thereof, and combinations thereof, whereby the dental article is provided with a color corresponding to a natural tooth shade; and wherein the dental article has a flexural strength of at least about 800 MPa. Corresponding methods are also described.

1 . A method for creating a shaded ceramic including the steps of:
 creating three or more uniquely shaded zirconia pigment powders, each having their own characteristic hue, by combining zirconia powder with a chemical component selected from the group consisting of Fe, Er, Co, Pr, Tb, Cr, Nd, Ce, V, Eu, Ho, Ni, and Cu salts, oxides, inorganic, organic, organo-metallic compounds thereof, and combinations thereof;   mixing together unpigmented zirconia powder with one or more of said pigment powders to achieve a predetermined shade powder;   pressing said predetermined shade powder to form a green block;   drying said green block;   pre-sintering said green block.   
     
     
         2 . A method for creating a dental ceramic comprising the method of  claim 1 , wherein zirconia powder comprises yttria stabilized tetragonal zirconia polycrystal (YTZP) powder. 
     
     
         3 . A method for creating a dental ceramic comprising the method of  claim 1 , with the further steps of milling the block to create a desired form, and sintering said form. 
     
     
         4 . A method for creating a dental ceramic comprising the method of  claim 1 , wherein the chemical component is added in the form of an aqueous or nonaqueous solution, emulsion, dispersion, gel or particulate. 
     
     
         5 . A method for creating a dental ceramic comprising the method of  claim 1 , wherein three uniquely shaded pigment powders each have their own characteristic hue in the yellow, pink and gray ranges. 
     
     
         6 . A shaded ceramic created by the method set forth in  claim 1 . 
     
     
         7 . A dental ceramic prosthesis created by the method set forth in  claim 1 .