Zirconia pre-sintered body suitable for dental use

Patent metadata

Field	Value
Publication number	US-12583794-B2
Application number	US-201917311518-A
Country	US
Kind code	B2
Filing date	Dec 26, 2019
Priority date	Dec 27, 2018
Publication date	Mar 24, 2026
Grant date	Mar 24, 2026

Abstract

The present invention provides a zirconia pre-sintered body that can be fired into a sintered body having translucency and strength suited for dental use (particularly, at the dental clinic), even with a short firing time. The present invention relates to a zirconia pre-sintered body comprising: zirconia; and a stabilizer capable of inhibiting a phase transformation of zirconia, wherein the zirconia predominantly comprises a monoclinic crystal system, and the zirconia pre-sintered body comprises a plurality of layers that differ from each other in the content of the stabilizer relative to the total mole of the zirconia and the stabilizer.

First claim

The invention claimed is:

1 . A zirconia pre-sintered body comprising:
zirconia; and a stabilizer capable of inhibiting a phase transformation of zirconia, wherein the zirconia predominantly comprises a monoclinic crystal system, wherein the zirconia pre-sintered body comprises a plurality of layers that differ from each other in a content of the stabilizer relative to a total mol % of the zirconia and the stabilizer, wherein the stabilizer is yttria, wherein the zirconia pre-sintered body has a fraction f y of more than 0% as calculated from mathematical expression (1):

⁢

⁢

f
y

⁡

(
%
)

=

I
y

⁡

(

1
⁢
1
⁢
1

)

I
y

⁡

(

1
⁢
1
⁢
1

)

+

I
m

⁡

(

1
⁢
1
⁢
1

)

+

I
m

⁡

(

1
⁢
1

-
1

)

+

I
t

⁡

(

1
⁢
1
⁢
1

)

+

I
c

⁡

(

1
⁢
1
⁢
1

)

×
100

(
1
)

where I y ( 111 ) represents a peak intensity of a ( 111 ) plane of the yttria about 2θ=29° in an X-ray diffraction pattern using CuKα radiation,
I m ( 111 ) and I m ( 11 - 1 ) represent peak intensities of ( 111 ) plane and ( 11 - 1 ) plane, respectively, of the monoclinic crystal system of the zirconia in the X-ray diffraction pattern,
I t ( 111 ) represents a peak intensity of a ( 111 ) plane of a tetragonal crystal system of the zirconia in the X-ray diffraction pattern, and
I c ( 111 ) represents a peak intensity of a ( 111 ) plane of a cubic crystal system of the zirconia in the X-ray diffraction pattern, and
wherein the fraction f y is 13% or less, and
wherein, on a straight line extending along a first direction from one end to another end of the zirconia pre-sintered bod

Assignees

• Kuraray Noritake Dental Inc

Inventors

• Kato Shinichiro
• Ito Yoshihisa

Classifications

• C04B2235/9653

  Translucent or transparent ceramics other than alumina · CPC title

• C04B2235/765

  Tetragonal symmetry · CPC title

• C04B2235/762

  Cubic symmetry, e.g. beta-SiC · CPC title

• C04B2235/661

  Multi-step sintering · CPC title

• C04B2235/6567

  Treatment time · CPC title