Method of electrophoretic deposition of ceramic bodies for use in manufacturing dental appliances

• US 6,059,949 A
• Filed: 03/31/1998
• Issued: 05/09/2000
• Est. Priority Date: 04/23/1997
• Status: Expired due to Term

• Current Assignee: Cerel (Ceramics Technologies) Ltd.
• Original Assignee: Cerel (Ceramics Technologies) Ltd.
• Inventors: Sezin, Nina, Goldner, Roni, Liubovich, Sonja, Cherniak, Liudmila, Gal-Or, Leah
• Primary Examiner(s): Mayekar, Kishor
• Application Number:
  US09/052,166
• Time in Patent Office: 770 Days
• Field of Search: 204/490, 204/491, 204/484, 433/212.1, 433/222.1, 433/223, 433/206, 433/207
• US Class Current: 204/484
• CPC Class Codes: A61C 13/001 Electrophoresis coating
• CPC Class Codes: A61C 13/0022 Blanks or green, unfinished dental restoration parts
• CPC Class Codes: A61C 5/77 Methods or devices for making crowns
• CPC Class Codes: C04B 2111/00836 for medical or dental applications
• CPC Class Codes: C04B 2235/3217 Aluminum oxide or oxide forming salts thereof, e.g. bauxite, alpha-alumina
• CPC Class Codes: C04B 2235/3244 Zirconium oxides, zirconates, hafnium oxides, hafnates, or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/5445 submicron sized, i.e. from 0,1 to 1 micron
• CPC Class Codes: C04B 2235/608 Green bodies or pre-forms with well-defined density
• CPC Class Codes: C04B 2235/77 Density
• CPC Class Codes: C04B 2235/96 Properties of ceramic products, e.g. mechanical properties such as strength, toughness, wear resistance
• CPC Class Codes: C04B 28/14 containing calcium sulfate cements gypsum-paper plates E04C
• CPC Class Codes: C04B 35/10 based on aluminium oxide
• CPC Class Codes: C04B 35/119 with zirconium oxide
• CPC Class Codes: C04B 35/46 based on titanium oxides or titanates containing also zirconium or hafnium oxides, zirconates or hafnates C04B35/49
• CPC Class Codes: C04B 35/48 based on zirconium or hafnium oxides, zirconates, zircon or hafnates
• CPC Class Codes: C04B 35/6264 Mixing media, e.g. organic solvents
• CPC Class Codes: C04B 41/009 characterised by the material treated
• CPC Class Codes: C04B 41/4535 applied as a solution, emulsion, dispersion or suspension
• CPC Class Codes: C04B 41/4564 Electrolytic or electrophoretic processes, e.g. electrochemical re-alkalisation of reinforced concrete desalination C04B41/53
• CPC Class Codes: C04B 41/4578 Coating or impregnating of green ceramics or unset concrete
• CPC Class Codes: C04B 41/5022 : with vitreous materials composition of vitreous glazes and enamels C03C; ceramic pigments C09C1/0009
• CPC Class Codes: C04B 41/5116 : Ag or Au
• CPC Class Codes: C04B 41/69 : Metals
• CPC Class Codes: C04B 41/86 : Glazes; Cold glazes
• CPC Class Codes: C25D 1/14 : of inorganic material
• CPC Class Codes: C25D 13/02 : with inorganic material
• CPC Class Codes: H05K 1/0306 : Inorganic insulating substrates, e.g. ceramic, glass
• CPC Class Codes: H05K 3/022 : Processes for manufacturing precursors of printed circuits, i.e. copper-clad substrates

Abstract

A method for electrophoretic deposition of ceramic particles as a green body shaped as a dental appliance, the method comprising the steps of (a) forming a suspension of the ceramic particles in a first polar solvent, the ceramic particles constituting at least about 5% of the first suspension by weight; (b) passing a direct electrical current through the first suspension, using a deposition electrode shaped as the dental appliance to form a green body; (c) coating the green body with glass particles; and (d) sintering the resultant coated body for obtaining a glass coated all-ceramic dental appliance.

Claims

1. A method of manufacturing an all-ceramic dental appliance, the method comprising the steps of:

(a) electrophoretically depositing at least one layer including ceramic particles on a deposition electrode, said at least one layer forming a green body having sufficient structural rigidity so as to serve in manufacturing the all ceramic dental appliance; and

(b) removing said deposition electrode, thereby obtaining the all-ceramic dental appliance.

2. The method of claim 1, further comprising the step of depositing at least one layer of a sintering temperature meltable material on said green body.

3. The method of claim 2, wherein said sintering temperature meltable material is glass.

4. The method of claim 2, further comprising the step of sintering said green body.

5. The method of claim 4, wherein sintering is at 1100-1550°

C.

6. The method of claim 2, wherein depositing said at least one layer of said sintering temperature meltable material on said green body is effected by electrophoretic deposition of said temperature meltable material on said green body.

7. The method of claim 6, wherein said temperature meltable material is deposited on said green body from a suspension including a polar solvent.

8. The method of claim 7, wherein said suspension further including a charging agent.

9. The method of claim 2, wherein depositing said at least one layer of said sintering temperature meltable material on said green body is effected by brushing a suspension containing said temperature meltable material onto said green body.

10. The method of claim 1, further comprising the step of presintering said green body.

11. The method of claim 10, wherein said presintering is effected at about 1200°

C.

12. The method of claim 1, wherein said step of electrophoretically depositing said at least one layer including said ceramic particles on said deposition electrode is effected by a direct electrical current having at least one constant parameter selected from the group consisting of current density and voltage.

13. The method of claim 1, wherein said deposition electrode is a cathode.

14. The method of claim 13, wherein said step of electrophoretically depositing said at least one layer including said ceramic particles on said deposition electrode is effected by passing a direct electrical current between said deposition electrode and a counter electrode made of a material selected from the group consisting of noble metals and nickel.

15. The method of claim 1, wherein said deposition electrode is a duplicate dental die of a moldable material coated with a conductive paint.

16. The method of claim 15, wherein said moldable material is selected from the group consisting of gypsum, wax and polymers.

17. The method of claim 15, wherein said conductive paint is a silver paint.

18. The method of claim 1, wherein said step of electrophoretically depositing said at least one layer including said ceramic particles on said deposition electrode is effected by a direct electrical current having a current density between about 0.1 mA/cm² and about 5 mA/cm².

19. The method of claim 1, wherein said step of electrophoretically depositing said at least one layer including said ceramic particles on said deposition electrode is effected by a direct electrical current having a voltage of about 50 to about 400 volts.

20. The method of claim 1, wherein said ceramic particles are deposited from a suspension including at least one polar solvent.

21. The method of claim 20, wherein said at least one polar solvent is selected from the group consisting of a ketone and an alcohol.

22. The method of claim 1, wherein said ceramic particles are selected from the group consisting of alumina particles, zirconia particles, yttria-stabilized zirconia particles, ceria-stabilized zirconia particles, magnia-stabilized zirconia particles, titania particles, mixed alumina-zirconia particles, mixed alumina-titania particles, mixed zirconia-titania particles.

23. The method of claim 1, wherein said ceramic particles are deposited from a suspension including at least one a dispersant to said first suspension.

24. The method of claim 23, wherein said dispersant is selected from the group consisting of acetylacetone, chloracetic acid, phosphate ester, triethanolamine and menhaden fish oil.

25. The method of claim 1, wherein said at least one layer further includes co-electrophoretically deposited glass particles.

26. The method of claim 1, wherein said ceramic particles constituting at least about 5% of a suspension by weight.

27. The method of claim 1, wherein said deposition electrode is a consumable electrode.