# US 11,077,646 B2 · Zirconia composition, zirconia semi-sintered body and zirconia sintered body, as well as dental product

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 11,077,646 B2
- Document ID: US11077646B2
- Status: Granted
- Kind: B2
- Application number: 16/892,400
- Filed: 2020-06-04
- Published: 2020-09-24
- Granted: 2021-08-03
- Earliest claimed: 2014-12-26
- Assignees: Kuraray Noritake Dental Inc.
- Applicants: Kuraray Noritake Dental Inc.
- Inventors: Yoshihisa Ito; Yasutaka Kudo
- Web page: https://patentgrep.com/patent/US11077646B2

## CPC

- B32B 18/00: Layered products essentially comprising ceramics, e.g. refractory products
- A61C 7/14: Brackets (A61C7/28 takes precedence); Fixing brackets to teeth
- A61C 8/0012: {characterised by the material or composition, e.g. ceramics, surface layer, metal alloy (use of specific materials A61K6/00)}
- A61C 13/082: {Cosmetic aspects, e.g. inlays; Determination of the colour (A61C19/10 takes precedence)}
- A61C 13/083: Porcelain or ceramic teeth {(A61C13/081 takes precedence; preparations A61K6/80)}
- C04B 35/486: Fine ceramics
- A61C 13/0022: {Blanks or green, unfinished dental restoration parts}
- A61C 13/09: {Composite teeth, e.g. front and back section (A61C13/0835, A61C13/1023 take precedence)}; Multilayer teeth
- C04B 2235/3217: Aluminum oxide or oxide forming salts thereof, e.g. bauxite, alpha-alumina
- C04B 2235/3225: Yttrium oxide or oxide-forming salts thereof
- C04B 2235/3232: Titanium oxides or titanates, e.g. rutile or anatase
- C04B 2235/3239: Vanadium oxides, vanadates or oxide forming salts thereof, e.g. magnesium vanadate
- C04B 2235/3246: Stabilised zirconias, e.g. YSZ or cerium stabilised zirconia
- C04B 2235/3248: Zirconates or hafnates, e.g. zircon
- C04B 2235/3279: Nickel oxides, nickalates, or oxide-forming salts thereof
- C04B 2235/3418: Silicon oxide, silicic acids or oxide forming salts thereof, e.g. silica sol, fused silica, silica fume, cristobalite, quartz or flint
- C04B 2235/9653: Translucent or transparent ceramics other than alumina
- C04B 2235/9661: Colour
- B32B: LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- A61C: DENTISTRY; APPARATUS OR METHODS FOR ORAL OR DENTAL HYGIENE (non-driven toothbrushes A46B; {tongue scrapers A61B17/24;} preparations for dentistry A61K6/00; preparations for cleaning the teeth or mouth A61K8/00, A61Q11/00)
- C04B: LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE {(roofing granules E04D7/005)}; CERAMICS (devitrified glass-ceramics C03C10/00); REFRACTORIES; TREATMENT OF NATURAL STONE

## Abstract

A zirconia composition, a zirconia semi-sintered body, a zirconia sintered body, and a dental product are provided. The zirconia sintered body contains 4 mol % to 7 mol % of yttria as stabilizer, and a shielding material. The zirconia sintered body comprises first region and second region having a higher content ratio of the shielding material than the first region. Difference between content ratio of yttria in the first region and that of yttria in the second region is 1 mol % or less.

## Claims

### Claim 1

A composition, comprising:
a partially stabilized zirconia comprising from 4 mol % to 7 mol % of yttria as a stabilizer and a light shielding material,
wherein
the composition comprises a first region and a second region having a higher content ratio of the light shielding material than the first region, and
the light shielding material is at least one selected from a group consisting of silicon oxide, aluminium oxide, titanium oxide, and a complex oxide of zirconium and silicon.

### Claim 2

A semi-sintered body, comprising:
a partially stabilized zirconia containing from 4 mol % to 7 mol % of yttria as a stabilizer, and a light shielding material,
wherein
the semi-sintered body comprises a first region and a second region having a higher content ratio of the light shielding material than the first region, and
the light shielding material is at least one selected from a group comprising silicon oxide, aluminium oxide, titanium oxide, and a complex oxide of zirconium and silicon.

### Claim 3 (depends on 2)

The semi-sintered body according to claim 2, wherein:
the semi-sintered body further comprises a third region between the first region and the second region, and
a content ratio of the light shielding material in the third region is higher than a content ratio of the light shielding material in the first region and lower than a content ratio of the light shielding material in the second region.

### Claim 4 (depends on 3)

The semi-sintered body according to claim 3, wherein
the semi-sintered body further comprises a fourth region between the third region and the second region, and
a content ratio of the light shielding material in the fourth region is higher than the content ratio of the light shielding material in the third region and lower than the content ratio of the light shielding material in the second region.

### Claim 5 (depends on 2)

The semi-sintered body according to claim 2, wherein fluctuation in the content ratio of yttria in each of the regions is 1 mol % or less.

### Claim 6 (depends on 2)

The semi-sintered body according to claim 2, wherein:
the semi-sintered body comprises a plate shape having a first surface and a second surface on an opposite side to the first surface,
the first region is arranged on the side of the first surface, and
the second region is arranged on the side of the second surface.

### Claim 7 (depends on 1)

A semi-sintered body obtained by firing the composition according to claim 1 at 800° C. to 1200° C.

### Claim 8 (depends on 1)

The composition of claim 1, wherein a difference between a content ratio of yttria in the first region and a content ratio of yttria in the second region is 1 mol % or less.

### Claim 9 (depends on 1)

The composition of claim 1, wherein the first region and the second region are laminated.

### Claim 10 (depends on 1)

The composition of claim 1, further comprising a third region between the first region and the second region, wherein a content ratio of the light shielding material in the third region is higher than a content ratio of the light shielding material in the first region and lower than a content ratio of the light shielding material in the second region.

### Claim 11 (depends on 10)

The composition of claim 10, further comprising a fourth region between the third region and the second region, wherein a content ratio of the light shielding material in the fourth region is higher than the content ratio of the light shielding material in the third region and lower than the content ratio of the light shielding material in the second region.

### Claim 12 (depends on 11)

The composition of claim 11, wherein, with respect to thickness in a laminated direction of each region,
a thickness of the first region is from 30% to 40% of a total thickness,
a thickness of the second region is from 30% to 40% of the total thickness,
a thickness of the third region is from 10% to 20% of the total thickness, and
a thickness of the fourth region is from 10% to 20% of the total thickness.

### Claim 13 (depends on 1)

The composition of claim 1, wherein the light shielding material further comprises at least one selected from a group consisting of a coloring agent and a fluorescence agent.

### Claim 14 (depends on 1)

The composition of claim 1, wherein the content of yttria is from 5.3 mol % to 6.2 mol %.