Controlled pore size ceramics particularly for orthopaedic and dental applications

• US 4,737,411 A
• Filed: 11/25/1986
• Issued: 04/12/1988
• Est. Priority Date: 11/25/1986
• Status: Expired due to Fees

• Current Assignee: University of Dayton
• Original Assignee: University of Dayton
• Inventors: Graves, George A. Jr., McCullum, Dale E., Goodrich, Steven M.
• Primary Examiner(s): Kittle, John E.
• Assistant Examiner(s): Ducker, Susan S.
• Application Number:
  US06/934,771
• Time in Patent Office: 504 Days
• Field of Search: 428/403, 428/404, 433/167, 433/201.1, 433/212.1, 433/222.1, 623/16, 623/16 D, 623/16 E, 623/16 G, 100/35, 501/32, 427/215
• US Class Current: 428/403
• CPC Class Codes: A61C 8/0012 characterised by the material or composition, e.g. ceramics, surface layer, metal alloy use of specific materials A61K6/00
• CPC Class Codes: A61C 8/0013 with a surface layer, coating
• CPC Class Codes: A61F 2/28 Bones joints A61F2/30
• CPC Class Codes: A61F 2/30767 Special external or bone-contacting surface, e.g. coating for improving bone ingrowth
• CPC Class Codes: A61F 2/3094 Designing or manufacturing processes
• CPC Class Codes: A61F 2002/30242 spherical
• CPC Class Codes: A61F 2230/0071 spherical
• CPC Class Codes: A61F 2310/00179 Ceramics or ceramic-like structures
• CPC Class Codes: A61F 2310/00203 containing alumina or aluminium oxide
• CPC Class Codes: A61F 2310/00293 containing a phosphorus-containing compound, e.g. apatite
• CPC Class Codes: A61F 2310/00928 Coating or prosthesis-covering structure made of glass or of glass-containing compounds, e.g. of bioglass
• CPC Class Codes: A61K 6/17 Particle size
• CPC Class Codes: A61K 6/75 Apatite
• CPC Class Codes: A61K 6/807 comprising magnesium oxide
• CPC Class Codes: A61K 6/818 comprising zirconium oxide
• CPC Class Codes: A61K 6/836 Glass
• CPC Class Codes: A61K 6/887 Compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
• CPC Class Codes: A61L 27/10 Ceramics or glasses
• CPC Class Codes: A61L 27/12 Phosphorus-containing materials, e.g. apatite
• CPC Class Codes: A61L 27/56 Porous materials, e.g. foams or sponges
• CPC Class Codes: C03C 3/16 : containing phosphorus
• CPC Class Codes: C03C 3/247 : containing fluorine and phosphorus
• CPC Class Codes: C03C 4/0007 : for biologically-compatible glass
• CPC Class Codes: C03C 4/0014 : Biodegradable glass
• CPC Class Codes: C04B 14/30 : Oxides other than silica ferrites C04B14/363
• CPC Class Codes: C04B 20/1055 : with inorganic materials
• CPC Class Codes: C04B 2111/00836 : for medical or dental applications
• CPC Class Codes: C04B 32/005 : Artificial stone obtained by melting at least part of the composition, e.g. metal C04B28/36 and C03C take precedence; cast stone from molten slag C04B5/00; artificial stone obtained by melting the polymeric ingredient of the composition C04B26/00
• CPC Class Codes: C04B 35/00 : Shaped ceramic products characterised by their composition porous ceramic products C04B38/00; ceramic articles characterised by particular shape, see the relevant classes, e.g. linings for casting ladles, tundishes, cups or the like B22D41/02; ceramic substrates for microelectronic semi-conductors H01L23/15; Ceramics compositions containing free metal bonded to carbides, diamond, oxides, borides, nitrides, silicides, e.g. cermets, or other metal compounds, e.g. oxynitrides or sulfides other than as macroscopic reinforcing agents C22C; shaping of ceramics B28B; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products chemical preparation of powders of inorganic compounds C01; infiltration of sintered ceramic preforms with molten metal C04B41/51
• CPC Class Codes: C04B 38/0038 : by superficial sintering or bonding of particulate matter
• CPC Class Codes: C08L 29/04 : Polyvinyl alcohol; Partially hydrolysed homopolymers or copolymers of esters of unsaturated alcohols with saturated carboxylic acids
• CPC Class Codes: Y10T 428/2991 : Coated
• CPC Class Codes: Y10T 428/2993 : Silicic or refractory material containing [e.g., tungsten oxide, glass, cement, etc.]

Abstract

The present invention provides a ceramic composite having an open porous network and a controlled pore size comprising a plurality of ceramic particles having a fused glass coating and a method for producing the same. The ceramic particles are enveloped by and bonded to adjacent ceramic particles at their interfaces by the glass coating.

Claims

1. A ceramic composite having an open porous network of a controlled pore size comprising a plurality of ceramic particles having a coating of a fused glass on their surfaces, said ceramic particles being bonded to adjacent ceramic particles at their interfaces by said fused glass coating to provide an open porous network between said ceramic particles.

2. The ceramic composite of claim 1 wherein said ceramic particles are a material selected from the group consisting of Al₂ O₃, MgO, ZrO₂, and SiC.

3. The ceramic composite of claim 1 wherein said ceramic composite is useful for dental and orthopaedic implants and said ceramic particles are a bone ingrowth promoting material.

4. The ceramic composite of claim 3 wherein said ceramic particles are a nonresorbable bone ingrowth promoting material.

5. The ceramic composite of claim 4 wherein said nonresorbable bone ingrowth promoting material is selected from the group consisting of hydroxyapatite, aluminum oxide, and pyrolytic carbon.

6. The ceramic composite of claim 3 wherein said ceramic particles are a resorbable bone ingrowth promoting material.

7. The ceramic composite of claim 6 wherein said resorbable bone ingrowth promoting material is selected from the group consisting of calcium aluminate, calcium phosphates, calcium aluminophosphates, and calcium sulfates.

8. The ceramic composite of claim 7 wherein said ceramic composite has a pore size of about 20 to 150 microns.

9. The ceramic composite of claim 8 wherein said ceramic composite has a pore size of at least about 100 microns.

10. The ceramic composite of claim 9 wherein said glass is resorbable.

11. The ceramic composite of claim 10 wherein said resorbable glass comprises calcium oxide (CaO) and phosphorus pentoxide (P₂ O₅).

12. The ceramic composite of claim 11 wherein said resorbable glass comprises by weight:

space="preserve" listing-type="tabular">______________________________________ CaO 5-50% P.sub.2 O.sub.5 50-95% CaF.sub.2 0-5% H.sub.2 O 0-5% XO 0-10% ______________________________________

wherein XO is a metal oxide selected from the group consisting of magnesium, zinc, strontium, sodium, potassium, lithium, and aluminum oxides.

13. The ceramic composite of claim 12 wherein said ceramic particles have a particle size of less than about 2000 microns.

14. The ceramic composite of claim 13 wherein said ceramic particles have a particle size of about 500 to 1000 microns.

15. The ceramic composite of claim 14 wherein the ratio of said ceramic particles to said glass coating based on the weight of said ceramic material is about 8:

1 to 14;

1.

16. The ceramic composite of claim 15 wherein said ceramic material is formed by coating said ceramic particles with fusible glass particles, molding said fusible glass coated ceramic particles into a desired shape, and sintering.

17. The ceramic composite of claim 16 wherein said ceramic particles are coated with said fusible glass particles in an agglomerator or a spray dryer.

24. The ceramic composite of claim 9 wherein said glass is non-resorbable.

18. Ceramic particles having a coating of a fused glass on the surface thereof.

19. The ceramic particles of claim 18 wherein said glass comprises calcium oxide (CaO) and phosphorus pentoxide (P₂ O₅).

20. The ceramic particles of claim 19 wherein said particles are a bone ingrowth promoting material.

21. A process for preparing a ceramic composite having a controlled pore size comprising the steps of:

coating ceramic particles with a glass,

molding said glass coated ceramic particles into a desired shape, and

sintering.

22. The process of claim 21 wherein said glass is a fusible glass powder.

23. The process of claim 22 wherein said ceramic particles are coated with said fusible glass particles in an agglomerator or a spray dryer.