Moldable dental material and method

• US 5,336,091 A
• Filed: 11/17/1992
• Issued: 08/09/1994
• Est. Priority Date: 12/02/1991
• Status: Expired due to Term

• Current Assignee: Aharon E. Whiteman, Itzhak Shoher
• Original Assignee: Aharon E. Whiteman, Itzhak Shoher
• Inventors: Whiteman, Aharon E., Shoher, Itzhak
• Primary Examiner(s): Lieberman, Paul
• Assistant Examiner(s): EINSMANN, MARGARET V
• Application Number:
  US07/977,637
• Time in Patent Office: 630 Days
• Field of Search: 106/35, 433/215, 433/207, 433/208, 433/228.1, 433/222.1, 164/80, 164/92.1, 164/97, 419/2, 419/23, 419/27
• US Class Current: 433/215
• CPC Class Codes: A61K 6/844 Noble metals
• CPC Class Codes: B22F 3/1121 by using decomposable, meltable or sublimatable fillers
• CPC Class Codes: B22F 3/26 Impregnating making ferrous alloys by impregnation C22C33/0242
• CPC Class Codes: B29C 43/006 Pressing and sintering powders, granules or fibres
• CPC Class Codes: C22C 1/0466 Alloys based on noble metals

Abstract

A moldable dental composition for use in forming or repairing dental restorations composed of a mixture of high- and low-fusing temperature metal particles and a volatile binder, composed substantially or entirely of wax, with the binder having a concentration of between thirty (30%) to eighty percent (80%) by volume of the mixture. The average particle size of the high-fusing metal particles are above one micron, and preferably between four microns and eighty microns in size. The composition is heat treated at a temperature to melt the low-fusing temperature metal particles and to eliminate the binder, leaving a porous metal structure with a void volume above thirty percent (30%). The voids are filled using a filler material of metal or ceramic.

Claims

1. A moldable dental composition comprising:

a uniform mixture of high-fusing temperature metal particles having an average particle size between about 4 to 80 microns, and a melting temperature above a heat treatment temperature;

low-fusing temperature metal particles having a melting temperature equal to or below said heat treatment temperature; and

a volatile binder, composed substantially or entirely of wax, with the binder in a concentration of between about thirty percent and eighty percent by volume, such that upon heat treatment at said heat treatment temperature, a porous metal structure is formed having a capillary network of voids and a void volume of between thirty to eighty percent.

2. A moldable dental composition, as defined in claim 1, wherein said high- and low-fusing temperature metal particles are precious metals.

3. A moldable dental composition, as defined in claim 2, wherein the low-fusing temperature metal component, relative to the high-fusing temperature component, is between twenty to eighty percent by volume.

4. A moldable dental composition, as defined in claim 2, wherein the low-fusing temperature metal component, relative to the high-fusing temperature component, is between forty to sixty-five percent by volume.

5. A moldable dental composition, as defined in claim 3, wherein said high-fusing temperature metal particles contain a concentration of platinum and palladium in a major proportion by weight, with at least fifty percent of the high-fusing particles, by weight, containing an alloy comprising at least twelve percent of platinum and palladium, respectively, and at least twenty percent gold.

6. A moldable dental composition, as defined in claim 3, wherein the void volume of said porous structure is between thirty-five to sixty-five percent.

7. A moldable dental composition, as defined in claim 6, further comprising a filler material for solidifying the porous metal structure formed upon heat treatment of said uniform mixture of high- and low-fusing metal particles, comprising a composition having a melting temperature below the melting temperature of said high-fusing metal component.

8. A moldable dental composition, as defined in claim 7, wherein said filler material comprises gold and a wax binder with the wax binder in a concentration of at least about thirty percent by volume of said filler material.

9. A moldable dental composition, as defined in claim 8, wherein said filler material further comprises an alloy of at least fifty percent by weight of gold and a metal selected from the group consisting of silver, copper, zinc, aluminum, magnesium, gallium, indium, tin, any of the platinum group metals, and elements from the third and fourth groups of elements of the periodic table of elements. fourth groups of elements of the periodic table of elements.

10. A moldable dental composition, as defined in claim 9, wherein at least fifty percent of the filler composition by weight comprises from between 90% to 98.5% gold and between 1.5% to 8.5% silver.

11. A moldable dental composition, as defined in claim 9, further comprising a flux.

12. A method for forming or repairing a dental restoration, comprising the steps of:

forming a mixture composed of particles of high-fusing temperature metal, particles of low-fusing temperature metal, and a binder, into a desired shape, with the binder composed substantially or entirely of wax in a concentration of at least about thirty percent by volume of the total mixture;

heat treating the mixture at a temperature below the melting temperature of the high-fusing temperature metal particles, and at or above the melting temperature of the low-fusing temperature metal particles, to form a porous structure corresponding to said conformed shape and composed of said metals with a void volume of between thirty to eighty percent;

adding a filler material to said porous structure; and

heat treating the structure at a temperature below the melting temperature of the high-fusing metal, but high enough to melt said filler material into said porous structure for solidifying said structure into a solid.

13. A method, as defined in claim 12, wherein said filler material comprises particles of gold and wax.

14. A method, as defined in claim 13, wherein said mixture is applied to a die or model of the tooth to be restored, and shaped into a coping of the desired shape for forming said structure.

15. A method, as defined in claim 14, wherein porcelain is applied to said solidified structure.

16. A method, as defined in claim 14, wherein said mixture is first formed into a strip, which is applied to said die or model of the tooth to be restored, and shaped into a desired configuration.

17. A method, as defined in claim 16, wherein said filler is in the form of a strip.