US4149893A
Expired / Lapsed
US
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Orthopedic and dental implant ceramic composition and process for preparing same
Assignee: Tokyo Medical and Dental University
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Filing: 1976-11-10
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Granted: 1979-04-17
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Expires: 1996-11-10
Abstract
Abstract Disclosed is an orthopedic and dental implant ceramic composition comprising hydroxyapatite and whitlockite. Said composition is prepared by blending 50 to 99.5% by weight of a crystalline hydroxyapatite and 0.5 to 50% by weight of whitlockite, and then, sintering the blend at a temperature of 900 DEG to 1,400 DEG C. Said crystalline hydroxyapatite is prepared by the solid phase reaction wherein a mixture of a calcium phosphate, having a Ca/P ratio of 1.5 to 1.67 by mole, and a stoichiometric amount or more of a calcium compound is heated at a temperature of 500 DEG to 1,000 DEG C. Said calcium compound is at least one compound selected from the group consisting of CaCO3, CaO, Ca(OH)2, CaF2, Ca(COO)2, Ca(NO3)2 and CaCl2.
Inventors
- 👤 Hideki Aoki
- 👤 Kazuo Kato
- 👤 Tsuneo Tabata
- 👤 Makoto Ogiso
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 14:41
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/01; C04B35/447; A; A61; A61C; A61C8/00; A61C8/0012; A61L; A61L27/00; A61L27/02; A61L27/12; A61F; A61F2310/00; A61F2310/00005; A61F2310/00179; A61F2310/00293
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
129 words
An orthopedic or dental implant ceramic composition comprising hydroxyapatite and whitlockite, said composition being prepared by blending 50 to 99.5% by weight of a crystalline hydroxyapatite and 0.5 to 50% by weight of whitlockite, and then, sintering the blend at a temperature of 900° to 1,400° C.; said crystalline hydroxyapatite being prepared by the solid phase reaction wherein a mixture of a calcium phosphate, having a Ca/P ratio of 1.5 to 1.67 by mole, and a stoichiometric amount or more of a calcium compound is heated at a temperature of 500° to 1,000° C.; said calcium compound being at least one compound selected from the group consisting of CaCO 3 , CaO, Ca(OH) 2 , CaF 2 , Ca(COO) 2 , Ca(NO 3 ) 2 and CaCl hd 2.
Claim 2
Dependent Claim
129 words
An orthopedic or dental implant ceramic composition comprising hydroxyapatite and whitlockite, said composition being prepared by blending 50 to 99.5% by weight of a crystalline hydroxyapatite and 0.5 to 50% by weight of whitlockite, and then, sintering the blend at a temperature of 900° to 1,400° C.; said crystalline hydroxyapatite being prepared by the solid phase reaction wherein a mixture of a calcium phosphate, having a Ca/P ratio of 1.5 to 1.67 by mole, and a stoichiometric amount or more of a calcium compound is heated at a temperature of 500° to 1,000° C.; said calcium compound being at least one compound selected from the group consisting of CaCO 3 , CaO, Ca(OH) 2 , CaF 2 , Ca(COO) 2 , Ca(NO 3 ) 2 and CaCl hd 2.
Claim 3
Dependent Claim
75 words
A composition according to claim 1, wherein at least one compound selected from the group consisting of MgO, Na 2 O, K 2 O, CaF 2 , Al 2 O 3 , SiO 2 , Fe 2 O 3 , MnO 2 , ZnO and C is further contained, added to the blend of hydroxyapatite and whitlockite in an amount of 0.1 to 45% based on the weight of said blend of hydroxyapatite and whitlockite.
Claim 4
Dependent Claim
127 words
A process for preparing an orthopedic and dental implant ceramic composition, which comprises blending 50 to 99.5% by weight of a crystalline hydroxyapatite and 0.5 to 50% by weight of whitlockite, and then, sintering the blend at a temperature of 900° to 1,400° C., said crystalline hydroxyapatite being prepared by the solid phase reaction wherein a mixture of a calcium phosphate having a Ca/P ratio of 1.5 to 1.67 by mole and a stoichiometric amount or more of a calcium compound is heated at a temperature of 500° to 1,000° C.; said calcium compound being at least one compound selected from the group consisting of CaCO 3 , CaO, Ca(OH) 2 , CaF 2 , Ca(COO) 2 , Ca(NO 3 ) 2 , and CaCl 2 .
Claim 5
Dependent Claim
127 words
A process for preparing an orthopedic and dental implant ceramic composition, which comprises blending 50 to 99.5% by weight of a crystalline hydroxyapatite and 0.5 to 50% by weight of whitlockite, and then, sintering the blend at a temperature of 900° to 1,400° C., said crystalline hydroxyapatite being prepared by the solid phase reaction wherein a mixture of a calcium phosphate having a Ca/P ratio of 1.5 to 1.67 by mole and a stoichiometric amount or more of a calcium compound is heated at a temperature of 500° to 1,000° C.; said calcium compound being at least one compound selected from the group consisting of CaCO 3 , CaO, Ca(OH) 2 , CaF 2 , Ca(COO) 2 , Ca(NO 3 ) 2 , and CaCl 2 .
Claim 6
Dependent Claim
76 words
A process according to claim 3, wherein at least one compound selected from the group consisting of MgO, Na 2 O, K 2 O, CaF 2 , Al 2 O 3 , SiO 2 , Fe 2 O 3 , MnO 2 , ZnO and C is added to the blend of hydroxyapatite and whitlockite in an amount of 0.1 to 45% based on the weight of said blend of hydroxyapatite and whitlockite before the sintering.
Claim 7
Dependent Claim
24 words
A process according to claim 3, wherein the blend of hydroxyapatite and whitlockite is dressed into a grain size of 20 to 300 mesh.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-04-16 | 1982-10-16 | 1983-04-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-04-16 | 1986-10-16 | 1987-04-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-04-16 | 1990-10-16 | 1991-04-17 | $7700.00 | Window Closed / Lapsed |