Zirconia pre-sintered body suitable for dental use

Patent metadata

Field	Value
Publication number	US-2022017423-A1
Application number	US-201917311518-A
Country	US
Kind code	A1
Filing date	Dec 26, 2019
Priority date	Dec 27, 2018
Publication date	Jan 20, 2022
Grant date	—

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

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, and 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 mole of the zirconia and the stabilizer.

2 . The zirconia pre-sintered body according to claim 1 , wherein the monoclinic crystal system accounts for at least 55% of the zirconia.

3 . The zirconia pre-sintered body according to claim 1 , wherein the monoclinic crystal system accounts for at least 75% of the zirconia.

4 . The zirconia pre-sintered body according to claim 1 , wherein at least a part of the stabilizer is undissolved in the zirconia as a solid solution.

5 . The zirconia pre-sintered body according to claim 1 , wherein, on a straight line extending along a first direction from one end to the other end of the zirconia pre-sintered body, the content of the stabilizer relative to the total mole of the zirconia and the stabilizer shows unchanging patterns of increase and decrease from the one end toward the other end.

6 - 7 . (canceled)

8 . The zirconia pre-sintered body according to claim 1 , wherein the stabilizer is yttria.

9 . The zirconia pre-sintered body according to claim 8 , wherein, on a straight line extending along a first direction from one end to the other end of the zirconia pre-sintered body, a content of the yttria relative to a total mole of the zirconia and the yttria shows unchanging patterns of increase and decrease from the one end toward the other end,
the content of the yttria relative to the total mole of the zirconia and the yttria in a layer containing the one end is 4.5 mol % or more and 7.0 mol % or less, and the content of the yttria relative to the total mole of the zirconia and the yttria in a layer containing the other end is 2.0 mol % or more and less than 4.5 mol %.

10 . The zirconia pre-sintered body according to claim 8 , wherein, on a straight line extending along a first direction from one end to the other end of the zirconia pre-sintered body, a content of the yttria relative to a total mole of the zirconia and the yttria shows unchanging patterns of increase and decrease from the one end toward the other end, and
a difference in the content of the yttria relative to the total mole of the zirconia and the yttria between a layer containing the one end and a layer containing the other end is 4.0 mol % or less.

11 . The zirconia pre-sintered body according to claim 8 , wherein the zirconia pre-sintered body has an X-ray diffraction pattern with an yttria peak.

12 . The zirconia pre-sintered body according to claim 8 , wherein the zirconia pre-sintered body has a fraction f y of more than 0% as calculated from mathematical expression (1):

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Assignees

• Kuraray Noritake Dental Inc

Inventors

• Kato Shinichiro
• Ito Yoshihisa

Classifications

• C04B2235/6565

  Cooling rate · CPC title

• C04B2235/6562

  Heating rate · CPC title

• C04B2235/3225

  Yttrium oxide or oxide-forming salts thereof · CPC title

• C04B2235/9653

  Translucent or transparent ceramics other than alumina · CPC title

• C04B2235/96

  Properties of ceramic products, e.g. mechanical properties such as strength, toughness, wear resistance · CPC title