Dental zirconia blank having multilayer structure different in content of yttria

Abstract

To provide a dental zirconia blank which has high permeability, can reproduce a color tone close to a natural tooth and a strength to be able to tolerate in oral cavity. Furthermore, to provide a dental zirconia blank from which a prosthesis device of 4 or more units having high strength can be prepared. To provide a dental zirconia blank having a plurality of layers, comprising; a first layer consisting of a high permeability ceramic containing 91.6 to 96.5 mol % of zirconium oxide and 3.5 to 8.4 mol % of yttrium oxide, and a second layer consisting of a low permeability ceramic containing 95.6 to 98.5 mol % of zirconium oxide and 1.5 to 4.4 mol % of yttrium oxide, wherein a content rate of yttrium oxide in the low permeability ceramic is lower than a content rate of yttrium oxide in the high permeability ceramic by 0.5 to 5.4 mol %, and the first layer is positioned at one end of the plurality of layers in a layering direction.

Dependencies are inferred from the claim text.