Resorptive bone ceramic on the basis of tricalcium phosphate
First Claim
1. A process for the preparation of a tricalcium phosphate resorptive bone ceramic, wherein natural bone material is separated from soft tissues, and remaining organic substances are removed by pyrolysis, and resulting bone material is subsequently treated with phosphate carrier and then subjected to a sintering step, said process comprising:
- removing tissues from natural bone material;
drying the bone material for a predetermined period at an increased temperature of not more than about 150°
C.;
thereafter increasing the temperature to about 550°
C. in a reducing atmosphere or an atmosphere deficient in air;
heating the bone material to a temperature of about 550°
C.-800°
C. under an excess of air, which is in excess of that needed for removal of remaining organic substances by pyrolysis;
cooling the bone material;
treating the bone material with a stoichiometric amount of phosphate carrier to convert hydroxyapatite into tricalcium phosphate; and
sintering the resultant material at a temperature of about 1125°
-1670°
C.
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Accused Products
Abstract
The invention relates to a process for the preparation of a resorptive bone ceramic on the basis of tricalcium phosphate which can be used as a bone replacement material. In the process, natural bone material, freed from the soft tissues, is used as the starting material. The remaining organic substances are removed from this starting material by pyrolysis. The remaining bone material, which consists virtually completely of hydroxyapatite, is subsequently treated with a phosphate carrier and then subjected to a sintering step.
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Citations
15 Claims
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1. A process for the preparation of a tricalcium phosphate resorptive bone ceramic, wherein natural bone material is separated from soft tissues, and remaining organic substances are removed by pyrolysis, and resulting bone material is subsequently treated with phosphate carrier and then subjected to a sintering step, said process comprising:
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removing tissues from natural bone material; drying the bone material for a predetermined period at an increased temperature of not more than about 150°
C.;thereafter increasing the temperature to about 550°
C. in a reducing atmosphere or an atmosphere deficient in air;heating the bone material to a temperature of about 550°
C.-800°
C. under an excess of air, which is in excess of that needed for removal of remaining organic substances by pyrolysis;cooling the bone material; treating the bone material with a stoichiometric amount of phosphate carrier to convert hydroxyapatite into tricalcium phosphate; and sintering the resultant material at a temperature of about 1125°
-1670°
C. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A process for preparation of tricalcium phosphate resorptive bone ceramic, comprising:
sintering tricalcium phosphate bone material at a temperature of about 1125°
-1670°
C. wherein said material is derived from natural bone material which has been dried at an increased temperature, for a predetermined period, of not more than about 150°
C., thereafter treated at a further increased temperature of not more than about 550°
C. in a reducing atmosphere or air-deficient atmosphere, heated under an excess of air, which is in excess of that needed for removal of remaining organic substances by pyrolysis, at a temperature of about 550°
C.-800°
C., cooled and then treated with a stoichiometric amount of phosphate carrier to convert the hydroxyapatite of the bone material to tricalcium phosphate.
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15. A resorptive bone ceramic comprising tricalcium phosphate:
said ceramic material consisting essentially of sintered tricalcium phosphate which results from treated hydroxyapatite derived from natural bone material and wherein the porous fine structure, characteristic of natural bone, remains intact.
Specification