	US 11,986,362 B2
	Zirconia mill blank for dental cutting and machining and preparing method thereof
Kazumichi Nonaka, Kyoto (JP); and Shuhei Takahashi, Kyoto (JP)
Assigned to SHOFU INC., Kyoto (JP)
Filed by SHOFU INC., Kyoto (JP)
Filed on Aug. 21, 2019, as Appl. No. 16/546,426.
Claims priority of application No. 2018-155064 (JP), filed on Aug. 22, 2018; and application No. 2018-155065 (JP), filed on Aug. 22, 2018.
Prior Publication US 2020/0170753 A1, Jun. 4, 2020
Int. Cl. A61C 1/08 (2006.01); A61C 3/02 (2006.01); B22F 3/04 (2006.01); B22F 3/24 (2006.01); C04B 35/622 (2006.01); C04B 38/00 (2006.01); C04B 111/00 (2006.01)

CPC A61C 1/08 (2013.01) [A61C 3/02 (2013.01); B22F 3/04 (2013.01); C04B 35/622 (2013.01); C04B 38/0074 (2013.01); B22F 2003/242 (2013.01); B22F 2302/25 (2013.01); B22F 2304/056 (2013.01); C04B 2111/00836 (2013.01); C04B 2235/3225 (2013.01); C04B 2235/602 (2013.01)]

15 Claims

1. A zirconia mill blank for dental cutting and machining, wherein;

the zirconia mill blank for dental cutting and machining has a porosity within a range of 15 to 30% as calculated from following formula (1):

Porosity (%)=pore volume/(pore volume+skeleton volume)×100 (1)

wherein the skeleton volume is a value calculated by the following formula:

skeleton volume (cm³/g)=1/true density(g/cm³), and

a pore diameter of the zirconia mill blank for dental cutting and machining is within a range of 50 to 200 nm, wherein the pore diameter is a diameter of a micro pore having a median value of the pore volume measured by a mercury intrusion method.