US4963145A
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US
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Porous ceramic material and processes for preparing same
Assignee: Sumitomo Cement Co Ltd
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Filing: 1989-03-20
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Granted: 1990-10-16
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Expires: 2009-03-20
Abstract
Abstract A porous ceramic material composed of a sintered porous body of a calcium phosphate compound is described. A multiplicity of capillary void paths having a diameter of 1 to 30 μm and a multiplicity of pores having a diameter of 1 to 600 μm are formed in the sintered porous body. At least part of the pores are connected to the exterior space of the sintered porous body through at least a part of the capillary voids. The porous ceramic material is valuable as a medical material, e.g., a substitute or prosthesis for bone or dental root, and also an electronic material and a genetic engineering material. When the porous ceramic material is embedded in a bone defect of human or animals, osteolytic cells, osteoblasts, erythrocytes and body fluid are selectively allowed to intrude through the porous ceramic material while almost no intrusion of osteoclasts and collagen fibers is allowed. Accordingly, the porous ceramic material can be utilized for inducing new-born bone, controlling resorption of bone with age, remedying bone defects.
Inventors
- 👤 Shigehide Takagi
- 👤 Shigeru Yamauchi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 08:56
CPC Classifications
C; C04; C04B; C04B38/00; C04B38/06; A; A61; A61L; A61L27/00; A61L27/02; A61L27/12; A61L27/50; A61L27/56; C04B38/063; C04B38/0635; C04B38/0645; C04B38/065; C04B38/10; C04B38/106; A61F; A61F2310/00; A61F2310/00005; A61F2310/00179; A61F2310/00293; A61L2400/00; A61L2400/18; C04B2111/00; C04B2111/00474; C04B2111/00836; C04B2111/00844
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
121 words
A porous ceramic material comprising a sintered porous body of a calcium phosphate compound, wherein a multiplicity of capillary void paths having a diameter in the range of 1 to 30 μm and a multiplicity of pores interconnected by said capillary void paths having a diameter of 3 to 600 μm are formed in the sintered porous body and at least part of said pores are connected to the exterior space of the sintered porous body through at least a part of said capillary void paths and wherein all of the capillary void paths have substantially the same diameters and said pores are substantially spherical, and the diameters of said capillary void paths are smaller than the diameters of said pores.
Claim 2
Dependent Claim
121 words
A porous ceramic material comprising a sintered porous body of a calcium phosphate compound, wherein a multiplicity of capillary void paths having a diameter in the range of 1 to 30 μm and a multiplicity of pores interconnected by said capillary void paths having a diameter of 3 to 600 μm are formed in the sintered porous body and at least part of said pores are connected to the exterior space of the sintered porous body through at least a part of said capillary void paths and wherein all of the capillary void paths have substantially the same diameters and said pores are substantially spherical, and the diameters of said capillary void paths are smaller than the diameters of said pores.
Claim 3
Dependent Claim
29 words
A ceramic material according to claim 1, wherein the atomic ratio of calcium to phosphorus in the calcium phosphate compound is in the range of from 1.30 to 1.80.
Claim 4
Dependent Claim
14 words
A ceramic material according to claim 1, wherein the calcium phosphate compound is hydroxyapatite.
Claim 5
Dependent Claim
23 words
A ceramic material according to claim 1, wherein the size of said pores is in the range of from 3 to 300 microns.
Claim 6
Dependent Claim
25 words
A ceramic material according to claim 1, wherein the diameter of the capillary void paths is in the range of from 1 to 20 microns.
Claim 7
Dependent Claim
18 words
A ceramic material according to claim 1, wherein the porous body has a porosity of 40 to 90%.
Claim 8
Independent Claim
158 words
A method for inducing a newborn bone which comprises filling or embedding in a defect of a bone of a human or animal, a porous ceramic material composed of a sintered porous body of a calcium phosphate compound, wherein a multiplicity of capillary void paths having a diameter of 1 to 30 μm and a multiplicity of pores interconnecting by said capillary void paths and having a diameter of 3 to 600 μm are formed in the sintered porous body and at least part of said pores are connected to the exterior space of the sintered porous body through at least a part of said capillary void paths, said capillary void paths having substantially the same diameters, said pores being substantially spherical and the diameters of said capillary void paths being smaller than the diameters of said pores, whereby a new-born bone is induced while intrusion of collagen fibers and osteoclasts into the porous ceramic material is restricted.
Claim 9
Independent Claim
158 words
A method for inducing a newborn bone which comprises filling or embedding in a defect of a bone of a human or animal, a porous ceramic material composed of a sintered porous body of a calcium phosphate compound, wherein a multiplicity of capillary void paths having a diameter of 1 to 30 μm and a multiplicity of pores interconnecting by said capillary void paths and having a diameter of 3 to 600 μm are formed in the sintered porous body and at least part of said pores are connected to the exterior space of the sintered porous body through at least a part of said capillary void paths, said capillary void paths having substantially the same diameters, said pores being substantially spherical and the diameters of said capillary void paths being smaller than the diameters of said pores, whereby a new-born bone is induced while intrusion of collagen fibers and osteoclasts into the porous ceramic material is restricted.
Claim 10
Dependent Claim
28 words
A method according to claim 7, wherein the atomic ratio of calcium to phosphorus in the calcium phosphate compound is in the range of from 1.30 to 1.80.
Claim 11
Dependent Claim
13 words
A method according to claim 7, wherein the calcium phosphate compound is hydroxyapatite.
Claim 12
Dependent Claim
22 words
A method according to claim 7, wherein the diameter of said pores is in the range of from 3 to 300 microns.
Claim 13
Dependent Claim
24 words
A method according to claim 7, wherein the diameter of the capillary void paths is in the range of from 1 to 20 microns.
Claim 14
Dependent Claim
17 words
A method according to claim 7, wherein the porous body has a porosity of 40 to 90%.
Claim 15
Dependent Claim
41 words
A ceramic material according to claim 1 wherein the diameter of said pores is in the range of from 3 to 300 microns and the diameter of the capillary void paths is in the range of from 1 to 20 microns.
Claim 16
Dependent Claim
35 words
A ceramic material according to claim 1 wherein the pores have diameters in the range of from more than 12 to 500 μm and the capillary void paths have a diameter of about 12 μm.
Claim 17
Dependent Claim
52 words
A ceramic material according to claim 1 which is comprised of a multiplicity of capillary void paths having a diameter of from 5 to 10 μm and a multiplicity of pores interconnected by the capillary void paths, said pores having diameters in the range of from more than 10 to 500 μm.
Claim 18
Dependent Claim
49 words
A ceramic material according to claim 1 which comprises a multiplicity of capillary void paths having a diameter of from 1 to 30 μm and a multiplicity of pores interconnected by said capillary void paths, said pores having a diameter in the range of from 100 to 500 μm.
Claim 19
Dependent Claim
25 words
A ceramic material according to claim 7 wherein the capillary void paths have a diameter in the range of from about 5 to 10 μm.
Claim 20
Dependent Claim
46 words
A ceramic material according to claim 1 which comprises capillary void paths having a diameter in the range of from 2 to 10 μm and a multiplicity of pores interconnected by said capillary void paths, said pores having a diameter of from 30 to 300 μm.
Claim 21
Dependent Claim
12 words
A ceramic material according to claim 1 wherein said pores are spherical.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-10-15 | 1994-04-16 | 1994-10-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-10-15 | 1998-04-16 | 1998-10-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-10-15 | 2002-04-16 | 2002-10-16 | $7700.00 | Window Closed / Lapsed |