Porous hydroxyapatite material for artificial bone substitute
Abstract
Abstract The sintered microporous hydroxyapatite material of the invention is useful as an artificial bone substitute material either in a granular and slurried from in a physiological saline solution used as a filling material for lost portions or cavities of bones or in a form of a shaped prosthetic bone substitute member. The inventive material is characteristic in the open pore structure of micropores with a pore diameter distribution in the range from 0.01 to 0.10 mm and a porosity in the range from 20 to 50%. When the material is used in the form of a granular bone filling, the particle diameter thereof should be in the range from 0.1 to 2.0 mm. When the material is used as the prosthetic bone substitute member, the shaped body should be formed of the matrix of the inventive microporous material and pores with a pore diameter distribution in the range from 0.2 to 2.0 mm. When an increased bending strength is desired, the prosthetic member should preferably have a core-and-crust structure of which the matrix of the core portion and the crust layer having a thickness of 0.1 to 2 mm are formed of the inventive microporous material, the core portion being formed of the matrix and pores of 0.2 to 2.0 mm diameter distribution throughout the matrix.
Inventors
- 👤 Susumu Takata
- 👤 Shoichi Wakabayashi
- 👤 Hiroyasu Noma
- 👤 Tatsuya Wakatsuki
Bibliographic Details
Claims Analysis
Total Claims: 10References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1989-12-15 | 1990-06-16 | 1990-12-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-12-15 | 1994-06-16 | 1994-12-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-12-15 | 1998-06-16 | 1998-12-16 | $7700.00 | Window Closed / Lapsed |