Method for producing bone filter of calcium phosphate

1. A method for producing a bone filler of calcium phosphate, comprising preparing a mixed liquid comprising a calcium solution and a phosphoric acid solution with a substrate of calcium phosphate existing therein, thereby precipitating calcium phosphate on said substrate to form a coating layer, and heat-treating the resultant composite comprising said substrate and said coating layer, wherein said substrate is made of hydroxyapatite.

2. The method for producing a bone filler of calcium phosphate according to claim 1 , wherein said coating layer is composed of calcium phosphate having a smaller Ca/P ratio than that of said substrate.

3. The method for producing a bone filler of calcium phosphate according to claim 2 , wherein said substrate has a Ca/P ratio of 1.6-1.9.

4. The method for producing a bone filler of calcium phosphate according to claim 3 , wherein said calcium solution and said phosphoric acid solution are mixed such that the resultant mixed liquid has a Ca/P ratio of 1.0-1.59.

5. The method for producing a bone filler of calcium phosphate according to claim 1 , wherein said substrate is a sintered body of hydroxyapatite.

6. The method for producing a bone filler of calcium phosphate according to claim 1 , wherein said mixed liquid has a pH of 4-9.

7. The method for producing a bone filler of calcium phosphate according to claim 1 , wherein a needle-shaped crystal of calcium phosphate is precipitated on said substrate.

8. The method for producing a bone filler of calcium phosphate according to claim 1 , wherein said heat treatment is carried out at a temperature of 700-1000° C.

9. A method for producing a bone filler of calcium phosphate, comprising:

preparing a mixture of a hydroxyapatite substrate and a calcium salt solution;

adding to the mixture an aqueous phosphoric acid solution, thereby precipitating calcium phosphate on the hydroxyapatite substrate to form a coating layer; and

heat-treating a resultant composite comprising the hydroxyapatite substrate and the coating layer.

10. A method for producing a bone filler of calcium phosphate, comprising preparing a mixed liquid comprising a calcium solution and a phosphoric acid solution with a substrate of calcium phosphate existing therein, thereby precipitating calcium phosphate on said substrate to form a coating layer, and heat-treating the resultant composite comprising said substrate and said coating layer, wherein said substrate comprises pores of about 20 nm diameter.

11. The method for producing a bone filler of calcium phosphate according to claim 10 , wherein said coating layer is composed of calcium phosphate having a smaller Ca/P ratio than that of said substrate.

12. The method for producing a bone filler of calcium phosphate according to claim 11 , wherein said substrate has a Ca/P ratio of 1.6-1.9.

13. The method for producing a bone filler of calcium phosphate according to claim 12 , wherein said calcium solution and said phosphoric acid solution are mixed such that the resultant mixed liquid has a Ca/P ratio of 1.0-1.59.

14. The method for producing a bone filler of calcium phosphate according to claim 10 , wherein said substrate is a sintered body of calcium phosphate.

15. The method for producing a bone filler of calcium phosphate according to claim 10 , wherein said mixed liquid has a pH of 4-9.

16. The method for producing a bone filler of calcium phosphate according to claim 10 , wherein a needle-shaped crystal of calcium phosphate is precipitated on said substrate.

17. The method for producing a bone filler of calcium phosphate according to claim 10 , wherein said heat treatment is carried out at a temperature of 700-1000° C.