US 12,213,849 B2
Dental zirconia blank having multilayer structure different in content of yttria
Rieko Aiba, Kyoto (JP); Shuhei Takahashi, Kyoto (JP); and Toshio Kitamura, Kyoto (JP)
Assigned to SHOFU INC., Kyoto (JP)
Filed by SHOFU INC., Kyoto (JP)
Filed on Mar. 19, 2019, as Appl. No. 16/357,373.
Claims priority of application No. 2018-052050 (JP), filed on Mar. 20, 2018; and application No. 2019-048083 (JP), filed on Mar. 15, 2019.
Prior Publication US 2019/0380815 A1, Dec. 19, 2019
Int. Cl. A61C 13/00 (2006.01); C04B 35/486 (2006.01)
CPC A61C 13/0022 (2013.01) [C04B 35/486 (2013.01); C04B 2235/3225 (2013.01); C04B 2235/3244 (2013.01); C04B 2235/9653 (2013.01)] 17 Claims
OG exemplary drawing
 
1. A dental zirconia blank consisting of;
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 %,
a ceramic powder constituting the high permeability ceramic and a ceramic powder constituting the low permeability ceramic have BET specific surface areas within a range of 5 to 20 m2/g, and
the ceramic powder constituting the high permeability ceramic and the ceramic powder constituting the low permeability ceramic have average primary particle diameters within a range of 10 to 1000nm.