EP0639366A1
Expired / Lapsed
EP
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Hydroxyapatite cement as bone or tooth replacement
Assignee: KINGSTAR TECHNOLOGY Ltd (UK)
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Filing: 1993-08-19
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Granted: —
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Expires: 2013-08-19
Abstract
Abstract In order to produce a hydroxyapatite cement useful in bone and tooth replacement, a calcium salt and a calcium phosphate are admixed in an aqueous solution of base, phosphate or organic acid capable of forming calcium ligand complexes, to deposit a hydroxyapatite cement, and/or the ratio of the total molar quantity of calcium to phosphate is in the range 1.3 : 1 to 1.8 : 1.
Inventors
- 👤 Chen Li
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-23 17:55
CPC Classifications
A; A61; A61L; A61L24/00; A61L24/02; A61K; A61K6/00; A61K6/80; A61K6/831; A61K6/838; A61K6/849; A61K6/864; A61K6/876; A61L24/0047; A61L24/0052; A61L24/0063; A61L27/00; A61L27/02; A61L27/12; C; C04; C04B; C04B28/00; C04B28/34; C04B28/346; A61F; A61F2310/00; A61F2310/00005; A61F2310/00179; A61F2310/00293; C04B2111/00; C04B2111/00474; C04B2111/00836
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
66 words
A process for producing a hydroxyapatite cement for use in bone or tooth replacement, comprising admixing a first calcium salt and at least one further calcium salt containing phosphate ions in an aqueous environment to deposit a hydroxyapatite cement, the ratio of the total molar quantity of calcium to the total molar quantity of phosphate being in the range 1.3 : 1 to 1.8 : 1.
Claim 2
Dependent Claim
12 words
A process according to Claim 1, wherein the aqueous environment is water.
Claim 3
Dependent Claim
74 words
A process for producing a hydroxyapatite cement useful in bone or tooth replacement, comprising admixing a first calcium salt and at least one further calcium salt containing phosphate ions in an aqueous environment so as to deposit a hydroxyapatite cement, characterised in that the aqueous environment essentially consists of an aqueous solution of base, an aqueous solution of a phosphate and/or an aqueous solution of an organic acid capable of forming calcium ligand complexes.
Claim 4
Dependent Claim
23 words
A process according to Claim 3, wherein the total concentration of base, phosphate and/or organic acid in solution is at least 0.2 M.
Claim 5
Dependent Claim
17 words
A process according to any of Claims 1 to 4, wherein the first calcium salt is Ca₄(PO₄)₂O.
Claim 6
Dependent Claim
18 words
A process according to Claim 3 or 4, wherein the first calcium salt is CaO, Ca(OH)₂ and/or CaCO₃.
Claim 7
Dependent Claim
26 words
A process according to any preceding Claim, wherein the further calcium salt is selected from Ca(H₂PO₄)₂, Ca(H₂PO₄)₂.H₂O, CaHPO₄, CaHPO₄.2H₂O, amorphous Ca₃(PO₄)₂, α-Ca₃(PO₄)₂, β-Ca₃(PO₄)₂ and/or Ca₈H₂ (PO₄)₆.5H₂O.
Claim 8
Dependent Claim
47 words
A process according to any preceding Claim, wherein the ratio of the total molar quantity of calcium to the total molar quantity of phosphate is in the range of 1.3 : 1 to 1.8 : 1, especially substantially in the range 1.6 :1 to 1.75 : 1.
Claim 9
Dependent Claim
16 words
A process according to Claim 8, therein said ratio is substantially equal to 1.67 : 1.
Claim 10
Dependent Claim
19 words
A process according to any preceding Claim, wherein the aqueous environment comprises an aqueous solution of NaOH and/or KOH.
Claim 11
Dependent Claim
21 words
A process according to any preceding Claim, wherein the aqueous environment comprises an aqueous solution of Na₃PO₄, Na₂HPO₄, NaH₂PO₄ and/or (NH₄)₂HPO₄.
Claim 12
Dependent Claim
20 words
A process according to any preceding Claim, wherein the aqueous environment comprises an aqueous solution of citric and/or phthalic acid.
Claim 13
Dependent Claim
61 words
A preparation for use in a process according to any preceding Claim and comprising, separately or together, a first calcium salt and at least one further calcium salt containing phosphate ions, said salts being sufficently finely divided to react together in an aqueous environment to deposit hydroxyapatite cement, said salts being provided as characterised in any of Claims 1 to 9.
Claim 14
Dependent Claim
61 words
A kit for producing a hydroxyapatite cement useful in bone and tooth replacement, comprising a liquid as defined in any of Claims 1 to 12, and, separately, a first calcium salt and at least one further calcium salt containing phosphate ions, said salts being optionally combined and sufficiently finely divided to react together in an aqueous environment to deposit hydroxyapatite cement.
Claim 15
Dependent Claim
27 words
A kit according to Claim 14, wherein the first calcium salt and the further calcium salt are provided as characterised in any of Claims 1 to 9.
References Cited (Backward Citations)
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