Claims
- 1. A method for making an implant, comprising the steps of:
(a) forming a mixture of a calcium phosphate and a polymer binder; and (b) selectively fusing the polymer binder to form an implant.
- 2. The method of claim 1, wherein the mixture comprises a plurality of agglomerated polymer-coated calcium phosphate particles.
- 3. The method of claim 2, wherein the polymer-coated particles are formed by spray drying an aqueous mixture of the calcium phosphate and the polymer binder.
- 4. The method of claim 1, further comprising the steps of infiltrating and thermally sintering the implant.
- 5. The method of claim 4, wherein the implant is infiltrated with a calcium phosphate solution.
- 6. The method of claim 1, further comprising the step of thermally sintering the implant.
- 7. The method of claim 6, further comprising the steps of infiltrating and again thermally sintering the implant.
- 8. The method of claim 7, wherein the implant is infiltrated with a calcium phosphate solution.
- 9. The method of claim 1, wherein the polymer binder is selectively fused with a laser beam.
- 10. The method of claim 9, wherein the polymer binder is selectively fused to replicate a desired geometrical shape.
- 11. The method of claim 9, wherein the polymer binder is selectively fused to form a desired geometrical shape.
- 12. The method of claim 10 or claim 11, wherein the desired geometrical shape is communicated to the laser beam by a computer.
- 13. The method of claim 12, wherein the desired geometrical shape is obtained from computed tomographic data.
- 14. The method of claim 12, wherein the desired geometrical shape is obtained from computer aided design software data.
- 15. The method of claim 1, wherein the calcium phosphate is prepared by reacting aqueous solutions of hydroxyapatite and phosphoric acid.
- 16. The method of claim 1, wherein the calcium phosphate is selected from the group consisting of:
calcium metaphosphate, calcium pyrophosphate, calcium phosphate with from about 25 to about 45 percent by weight calcium oxide, and calcium phosphate with from about 0.5 to about 2 percent by weight sodium oxide.
- 17. The method of claim 1, wherein the calcium phosphate comprises calcium metaphosphate.
- 18. The method of claim 1, wherein the calcium phosphate has a mean particle size of from about 5 to about 100 microns.
- 19. The method of claim 1, wherein the calcium phosphate has a mean particle size of from about 30 to about 50 microns.
- 20. The method of claim 1, wherein the polymer binder has the following properties:
(a) a Tg of between about 40° C. and about 100° C.; and (b) a melt flow index of between about 1 and about 50 g/10 minutes at 200° C. and 75 psi extrusion pressure.
- 21. The method of claim 20, wherein the polymer binder comprises a homopolymer, copolymer, or terpolymer of methyl methacrylate.
- 22. The method of claim 21, wherein the polymer binder comprises a poly(methyl methacrylate-co-n-butyl methacrylate) copolymer.
- 23. The implant produced in accordance with the method of claim 1.
- 24. The implant produced in accordance with the method of claim 9.
- 25. A method for making an implant, comprising the steps of:
(a) forming a mixture of a calcium phosphate and a polymer binder; (b) forming a layer of the mixture; (c) selectively fusing the polymer binder; and (d) repeating steps (b) and (c) a desired number of times to form a plurality of layers, wherein each layer is fused to adjacent layers to form an implant.
- 26. The method of claim 25, wherein the thickness of each layer is from about 3 to about 12 thousandths of an inch.
- 27. The method of claim 25, wherein the implant has a mean pore size of from about 100 to about 300 microns.
- 28. The method of claim 25, wherein the implant has a relative density of from about 50 to about 80%.
- 29. The implant produced in accordance with the method of claim 25.
- 30. A system for making an implant, comprising:
(a) a mixture of a calcium phosphate and a polymer binder; and (b) means for selectively fusing the polymer binder to form an implant.
- 31. The system of claim 30, further comprising means for forming layers of the mixture.
- 32. The system of claim 30 or 31, wherein the fusing means comprise a laser beam.
- 33. The system of claim 30, further comprising means for controlling the fusing means to form the implant in a desired geometrical shape.
- 34. The system of claim 33, wherein the controlling means comprise computed tomographic data.
- 35. The system of claim 33, wherein the controlling means comprise computer aided design software.
Government Interests
[0001] The U.S. government owns rights in the present invention as relevant developmental work was supported by DARPA/ONR (Grant No. N000014-92-J-1394).
Continuations (2)
|
Number |
Date |
Country |
Parent |
08832882 |
Apr 1997 |
US |
Child |
09765801 |
Jan 2001 |
US |
Parent |
08288120 |
Aug 1994 |
US |
Child |
08832882 |
Apr 1997 |
US |