Miserite crystallized glass for artificial tooth and method for coloring same

Patent metadata

Field	Value
Publication number	US-10913679-B2
Application number	US-201616330303-A
Country	US
Kind code	B2
Filing date	Oct 27, 2016
Priority date	Sep 2, 2016
Publication date	Feb 9, 2021
Grant date	Feb 9, 2021

Abstract

Disclosed are a miserite crystallized glass for an artificial tooth and a method for coloring same, the method enabling a production of a uniform shade without degrading the physical properties of a crystallized glass by means of simply adding a small amount of coloring additive powder when preparing the crystallized glass. A miserite crystallized glass for an artificial tooth according to the present invention is colored with any one of the shades in groups A, B, C and D of the Vita shade guide which is a tooth shade reference. The miserite crystallized glass has a miserite crystal phase as the main phase and comprises a hydroxyapatite crystal phase and a xonotlite crystal phase as additional phases.

First claim

What is claimed is:

1. A method for coloring a miserite-based crystallized glass for an artificial tooth, the method comprising:
(a) drying, weighing and ball-milling raw glass powders and coloring additive powders, wherein the raw glass powders includes SiO 2 , CaO, CaF 2 and K 2 O;
(b) introducing the ball-milled raw glass powders and coloring additive powders into a furnace, and calcining the powders therein at 950 to 1050° C. for 1 to 3 hours, and then cooling the powders to a room temperature;
(c) melting the calcined powders to form a glass;
(d) introducing the glass into a preheated mold at 450 to 550° C., preforming a thermal-stress removal heat-treatment of the glass at 450 to 550° C. for 1 to 3 hours, and cooling the glass to a room temperature; and
(e) heat-treating the glass to crystalline the glass, and cooling the glass to a room temperature to form a crystallized glass,
wherein in (c), the melting includes increasing the calcined powders to 1300 to 1400° C. at an increase rate of 8 to 12° C./min, and then performing melting of the powders at 1300 to 1400° C. for 10 to 60 minutes.

2. The method of claim 1 , wherein in (a), the weighing includes weighing the raw glass powders to have a composition of 50 to 55% by weight of SiO 2 , 24 to 30% by weight of CaO, 10 to 15% by weight of CaF 2 and 5 to 10% by weight of K 2 O.

3. The method of claim 1 , wherein in (a), the coloring additive powders includes at least one selected from a group consisting of Er 2 O 3 , Fe 2 O 3 , Cr 2 O 3 , Mn 2 O 3 , V 2 O 5 , CuO and CeO 2 .

4. The method of claim 1 , wherein in (a), the coloring additive powders are added in a content of 0.001 to 5 parts by weight based on 100 parts by weight of the raw glass powders.

5. The method of claim 1 , wherein in (e), the heat-treating includes:
a nucleation heat-treatment in which the glass is heat-treated at 580 to 630° C. for 30 minutes to 120 minutes;
a first crystallization heat-treatment in which the glass is heat-treated at 780 to 860° C. for 3 to 7 hours; and
a second crystallization heat-treatment in which the glass is heat-treated at 1000 to 1080° C. for 3 to 7 hours.

6. A miserite-based crystallized glass for an artificial tooth produced by a method comprising:
(a) drying, weighing and ball-milling raw glass powders and coloring additive powders, wherein the raw glass powders includes SiO 2 , CaO, CaF 2 and K 2 O;
(b) introducing the ball-milled raw glass powders and coloring additive powders into a furnace, and calcining the powders therein at 950 to 1050° C. for 1 to 3 hours, and then cooling the powders to a room temperature;
(c) melting the calcined powders to form a glass;
(d) introducing the glass into a preheated mold at 450 to 550° C., preforming a thermal-stress removal heat-treatment of the glass at 450 to 550° C. for 1 to 3 hours, and cooling the glass to a room temperature; and
(e) heat-treating the glass to crystalline the glass, and cooling the glass to a room temperature to form a crystallized glass,
wherein the miserite-based crystallized glass is colored to have a shade of one of groups A, B, C, or D of a Vita shade guide as a tooth shade reference, and
wherein the miserite-based crystallized glass has a miserite crystal phase as a main phase and has a hydroxyapatite crystal phase and a xonotlite crystal phase as additional phases.

7. The miserite-based crystallized glass of claim 6 , wherein the miserite-based crystallized glass exhibits a Vickers hardness 6.5 to 7.2 GPa, a fracture toughness 2.5 to 3.2 MPa·m −2 , a flexural strength 300 to 360 MPa and a 1 mm thickness-based visible-light transmittance 30 to 40%.

Assignees

• Univ Soonchunhyang Ind Acad Coop Found

Inventors

• Bang Jae-Chul
• Song Young-Joo
• Sung Si-Won
• Park Seung-Bum

Classifications

• C03C3/078

  containing an oxide of a divalent metal, e.g. an oxide of zinc · CPC title

• C03C4/02 Primary

  for coloured glass · CPC title

• C03C10/0009

  containing silica as main constituent · CPC title

• C03C3/087

  containing calcium oxide, e.g. common sheet or container glass · CPC title

• C03C4/0021

  for dental use · CPC title