Glass-ceramics, process of producing the glass-ceramics and dental crown using the glass-ceramics

• US 5,066,619 A
• Filed: 08/23/1990
• Issued: 11/19/1991
• Est. Priority Date: 09/05/1989
• Status: Expired due to Fees

• Current Assignee: Hoya Corporation
• Original Assignee: Hoya Corporation
• Inventors: Kasuga, Toshihiro, Kasuga, Tomoko
• Primary Examiner(s): Bell, Mark L.
• Application Number:
  US07/571,209
• Time in Patent Office: 453 Days
• Field of Search: 501/3, 106/35
• US Class Current: 501/3
• CPC Class Codes: A61K 6/807 comprising magnesium oxide
• CPC Class Codes: A61K 6/816 comprising titanium oxide
• CPC Class Codes: A61K 6/818 comprising zirconium oxide
• CPC Class Codes: A61K 6/822 comprising rare earth metal oxides
• CPC Class Codes: A61K 6/824 comprising transition metal oxides
• CPC Class Codes: A61K 6/833 Glass-ceramic composites
• CPC Class Codes: C03C 10/16 Halogen containing crystalline phase

Abstract

Disclosed is glass-ceramics produced by and a method of producing the glass-ceramics comprising the step of precipitating a calcium-potassium mica crystal consisting of Ca-K-Mg-Al-Si-O-F and at least one crystal selected from the group consisting of an enstatite crystal, an akermanite crystal and a diopside crystal, from glass containing components, in percent by weight, 2 to 17% of CaO, 0.5 to 5% of K₂ O, 20 to 35% of MgO, 30 to 50% of SiO₂, 5 to 30% of Al₂ O₃, and 1.5 to 14% of Fluorine (Calculated as F); or precipitating a calcium-potassium-sodium mica crystal consisting of Ca-K-Na-Mg-Al-Si-O-F and at least one crystal selected from the group consisting of an enstatite crystal, an akermanite crystal, a diopside crystal, an anorthite crystal and a richterite crystal, from glass containing components, in percent by weight, 2 to 17% of CaO, 0.5 to 5% of K_x O, 0.1 to 4% of Na₂ O, 15 to 35% of MgO, 30 to 49% of SiO₂, 5 to 30% of Al₂ O₃, and 1.5 to 14% of Fluorine (calculated as F). In the above method, the glass is heat treated successively at a temperature higher than its glass transition point by a range of from 10° to 100° C. and at a temperature higher than its glass transition point by a range of from 100° to 500° C. to thereby precipitate the above-mentioned matters.

Further disclosed is an artificial dental crown composed of the above-mentioned glass-ceramics.

Claims

1. A glass ceramics produced by precipitating from glass a calcium-potassium mica crystal consisting of Ca--K--Mg--Al--Si--O--F and at least one crystal selected from the group consisting of an enstatite crystal, an akermanite crystal and a diopside crystal, said glass containing components being present within the ranges as follows:

space="preserve" listing-type="tabular">______________________________________ Percent of weight ______________________________________ CaO 2 to 17 K.sub.2 O 0.5 to 5 MgO 20 to 35 SiO.sub.2 30 to 50 Al.sub.2 O.sub.3 5 to 30 Fluorine (calculated as F) 1.5 to 14. ______________________________________

2. A glass-ceramics according to claim 1, wherein said glass contains at least one component selected from the group consisting of SrO, TiO₂, Nb₂ O₅, Ta₂ O₅, Y₂ O₃ and ZrO₂ in an amount of 5% or less.

5. An artificial dental crown comprising the glass-ceramics of any one of claims 1, 2, 3 or 4.

3. Glass-ceramics produced by precipitating from glass a calcium-potassium-sodium mica crystal consisting of Ca--K--Na--Mg--Al--Si--O--F and at least one crystal selected from the group consisting of an enstatite crystal, an akermanite crystal, a diopside crystal, an anorthite crystal and a richterite crystal, said glass containing components being present within the ranges as follows:

space="preserve" listing-type="tabular">______________________________________ Percent by weight ______________________________________ CaO 2 to 17 K.sub.2 O 0.5 to 5 Na.sub.2 O 0.1 to 4 MgO 15 to 35 SiO.sub.2 30 to 49 Al.sub.2 O.sub.3 5 to 30 Fluorine (calculated as F) 1.5 to 14. ______________________________________

4. The glass-ceramics according to claim 3, wherein said glass contains at least one component selected from the group consisting of SrO, TiO₂, Nb₂ O₅, Ta₂ O₅, Y₂ O₃ and ZrO₂ in an amount of 5% of less.

6. An artificial dental crown comprising a glass-ceramics produced by the process of heating glass-containing components, present within the ranges as follows:

space="preserve" listing-type="tabular">______________________________________ Percent by weight ______________________________________ CaO 2 to 17 K.sub.2 O 0.5 to 5 MgO 20 to 35 SiO.sub.2 30 to 50 Al.sub.2 O.sub.3 5 to 30 Fluorine (calculated as F) 1.5 to 14 ______________________________________

successively at a temperature higher than the glass transition point by a range of from 10°

to 100°

C. and at a temperature higher than its glass transition point by a range of from 100°

to 500°

C., to thereby precipitate from the glass a calcium-potassium mica crystal consisting of Ca--K--Mg--Al--Si--O--F and at least one crystal selected from the group consisting of an enstatite crystal, an akermanite crystal and a diopside crystal.

7. The artificial dental crown of claim 6, wherein said glass contains at least one component selected from the group consisting of SrO, TiO₂, Nb₂ O₅, Ta₂ O₅, Y₂ O₃ and ZrO₂ in an amount of 5% or less.

8. An artificial dental crown comprising a glass-ceramics produced by heating glass-containing components, present within the ranges:

space="preserve" listing-type="tabular">______________________________________ Percent by weight ______________________________________ CaO 2 to 17 K.sub.2 O 0.5 to 5 Na.sub.2 O 0.1 to 4 MgO 15 to 35 SiO.sub.2 30 to 49 Al.sub.2 O.sub.3 5 to 30 Fluorine (calculated as F) 1.5 to 14 ______________________________________

successively at a temperature higher than its glass transition point by a range of from 10°

to 100°

C. and at a temperature higher than its glass transition point by a range of from 100°

to 500°

C., to thereby precipitate from the glass a calcium-potassium-sodium mica crystal consisting of Ca--K--Na--Mg--Al--Si--O--F and at least one crystal selected from the group consisting of an enstatite crystal, an akermanite crystal, a diopside crystal, an anorthite crystal and a richterite crystal.

9. The artificial dental crown of claim 8, wherein said glass contains at least one component selected from the group consisting of SrO, TiO₂, Nb₂ O₅, Ta₂ O₅, Y₂ O₃ and ZrO₂ in an amount of 5% or less.