US4097935A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hydroxylapatite ceramic
Assignee: Sanofi SA
•
Filing: 1977-01-31
•
Granted: 1978-07-04
•
Expires: 1997-01-31
Abstract
Abstract A novel ceramic form of hydroxylapatite and a novel ceramic product comprising a mixture of the latter and whitlockite, the preparation of these ceramics and dental restorative compositions and dental and surgical prosthetic materials containing the same are disclosed. Also described is a novel and improved process for producing polycrystalline ceramic oxides.
Inventors
- 👤 Michael Jarcho
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 09:58
CPC Classifications
A; A61; A61L; A61L27/00; A61L27/02; A61L27/12; A61F; A61F2/00; A61F2/02; A61F2/30; A61K; A61K6/00; A61K6/15; A61K6/17; A61K6/70; A61K6/71; A61K6/74; A61K6/75; A61K6/80; A61K6/802; A61K6/807; A61K6/813; C; C04; C04B; C04B35/00; C04B35/01; C04B35/447; A61F2310/00; A61F2310/00005; A61F2310/00179; A61F2310/00293
Claims Analysis
Total Claims: 46
Claim 1
Independent Claim
60 words
As an article of manufacture, substantially pure hydroxylapatite in the form of a translucent, isotropic, polycrystalline, sintered ceramic having an average crystallite size in the approximate range 0.2 to 3 microns, a density greater than approximately 98 percent of the theoretical density of hydroxylapatite and being further characterized by the absence of pores and by cleavage along smooth curved planes.
Claim 2
Dependent Claim
60 words
As an article of manufacture, substantially pure hydroxylapatite in the form of a translucent, isotropic, polycrystalline, sintered ceramic having an average crystallite size in the approximate range 0.2 to 3 microns, a density greater than approximately 98 percent of the theoretical density of hydroxylapatite and being further characterized by the absence of pores and by cleavage along smooth curved planes.
Claim 3
Dependent Claim
13 words
An article of manufacture according to claim 1 having a pH of 10-12.
Claim 4
Dependent Claim
34 words
An article of manufacture according to claim 1 wherein there is incorporated in said article an amount of fluoride ion effective in substantially reducing the rate of decomposition of said article by lactic acid.
Claim 5
Dependent Claim
16 words
An article of manufacture according to claim 1 shaped or formed substantially into a flat sheet.
Claim 6
Dependent Claim
19 words
A strong, dense, artificial bone or tooth prosthesis in the form of a polycrystalline ceramic according to claim 1.
Claim 7
Dependent Claim
58 words
As an article of manufacture, a strong, hard, dense, isotropic, polycrystalline sintered biphasic ceramic comprising as one phase from about 20 to 95 percent by weight of hydroxylapatite and as a second phase from about 5 to 80 percent by weight of whitlockite and being characterized by the absence of pores and by cleavage along smooth curved planes.
Claim 8
Dependent Claim
58 words
As an article of manufacture, a strong, hard, dense, isotropic, polycrystalline sintered biphasic ceramic comprising as one phase from about 20 to 95 percent by weight of hydroxylapatite and as a second phase from about 5 to 80 percent by weight of whitlockite and being characterized by the absence of pores and by cleavage along smooth curved planes.
Claim 9
Dependent Claim
34 words
An article of manufacture according to claim 6 wherein there is incorporated in said article an amount of fluoride ion effective in substantially reducing the rate of decomposition of said article by lactic acid.
Claim 10
Dependent Claim
16 words
An article of manufacture according to claim 6 shaped or formed substantially into a flat sheet.
Claim 11
Dependent Claim
19 words
A strong, dense, artificial bone or tooth prosthesis in the form of a polycrystalline ceramic according to claim 6.
Claim 12
Dependent Claim
101 words
The process which comprises reacting calcium ion with phosphate ion in aqueous medium at a pH of about 10-12 to produce a gelatinous precipitate of a phosphate of calcium having a molar ratio of calcium to phosphorus between the approximate molar ratio of calcium to phosphorus in whitlockite and that in hydroxylapatite, separating said gelatinous precipitate from solution, heating said gelatinous precipitate up to a temperature of at least approximately 1000° C. but below that at which appreciable decomposition of hydroxylapatite occurs, and maintaining said temperature for sufficient time to effect the sintering and substantially maximum densification of the resulting product.
Claim 13
Dependent Claim
101 words
The process which comprises reacting calcium ion with phosphate ion in aqueous medium at a pH of about 10-12 to produce a gelatinous precipitate of a phosphate of calcium having a molar ratio of calcium to phosphorus between the approximate molar ratio of calcium to phosphorus in whitlockite and that in hydroxylapatite, separating said gelatinous precipitate from solution, heating said gelatinous precipitate up to a temperature of at least approximately 1000° C. but below that at which appreciable decomposition of hydroxylapatite occurs, and maintaining said temperature for sufficient time to effect the sintering and substantially maximum densification of the resulting product.
Claim 14
Dependent Claim
79 words
A process according to claim 10 which comprises the steps of reacting calcium ion with phosphate ion in aqueous medium at a pH of about 10-12 to produce a gelatinous precipitate of hydroxylapatite, having a molar ratio of calcium to phosphorus of about 1.67, separating said gelatinous precipitate from the solution, heating said gelatinous precipitate up to a temperature in the approximate range 1000° C. to 1250° C. and maintaining said temperature for approximately 20 minutes to 3 hours.
Claim 15
Dependent Claim
25 words
A process according to claim 11 wherein said calcium ion is provided by calcium nitrate and said phosphate ion is provided by diammonium hydrogen phosphate.
Claim 16
Dependent Claim
24 words
A process according to claim 12 wherein said temperature is maintained at approximately 1100° C. to 1200° C. for approximately 0.5 to 1 hour.
Claim 17
Dependent Claim
17 words
A process according to claim 13 wherein said temperature is maintained at 1100° C. for 1 hour.
Claim 18
Dependent Claim
23 words
A process according to claim 11 wherein up to about 3 molar percent additional calcium ion is added to said precipitate of hydroxylapatite.
Claim 19
Dependent Claim
34 words
A process according to claim 11 wherein about 0.4 to 0.6 percent by weight of an organic binder is added to said precipitate of hydroxylapatite, said organic binder being volatilized during said heating process.
Claim 20
Dependent Claim
12 words
A process according to claim 16 wherein said organic binder is collagen.
Claim 21
Dependent Claim
47 words
A process according to claim 11 wherein about 5 to 25 percent by weight of an organic binder is added to said precipitate of hydroxylapatite, said organic binder being volatilized during said heating process and thereby resulting in production of a porous form of the ceramic article.
Claim 22
Dependent Claim
16 words
A process according to claim 18 wherein said organic binder is powdered cellulose, cotton, or collagen.
Claim 23
Dependent Claim
24 words
A process according to claim 11 wherein about 0.01 to 1 percent by weight of fluoride ion is added to said precipitate of hydroxylapatite.
Claim 24
Dependent Claim
31 words
A process according to claim 11 wherein the article produced thereby is allowed to stand in about 0.5 to 5 percent aqueous sodium fluoride for about 12 hours to five days.
Claim 25
Dependent Claim
87 words
A process according to claim 10 which comprises the steps of reacting calcium ion with phosphate ion in aqueous medium at a pH of about 10-12 to produce a gelatinous precipitate of calcium phosphate having a molar ratio of calcium to phosphorus substantially less than 1.67 but not less than about 1.50, separating said gelatinous precipitate from the solution, heating said gelatinous precipitate up to a temperature in the approximate range 1000° C. to 1350° C. and maintaining said temperature for approximately 20 minutes to 3 hours.
Claim 26
Dependent Claim
25 words
A process according to claim 22 wherein said calcium ion is provided by calcium nitrate and said phosphate ion is provided by diammonium hydrogen phosphate.
Claim 27
Dependent Claim
35 words
A process according to claim 22 wherein about 0.4 to 0.6 percent by weight of an organic binder is added to said precipitate of calcium phosphate, said organic binder being volatilized during said heating process.
Claim 28
Dependent Claim
12 words
A process according to claim 24 wherein said organic binder is collagen.
Claim 29
Dependent Claim
48 words
A process according to claim 22 wherein about 5 to 25 percent by weight of an organic binder is added to said precipitate of calcium phosphate, said organic binder being volatilized during said heating process and thereby resulting in production of a porous form of the ceramic article.
Claim 30
Dependent Claim
16 words
A process according to claim 26 wherein said organic binder is powdered cellulose, cotton or collagen.
Claim 31
Dependent Claim
25 words
A process according to claim 22 wherein about 0.01 to 1 percent by weight of fluoride ion is added to said precipitate of calcium phosphate.
Claim 32
Dependent Claim
31 words
A process according to claim 22 wherein the article produced thereby is allowed to stand in about 0.5 to 5 percent aqueous sodium fluoride for about 12 hours to five days.
Claim 33
Dependent Claim
44 words
In a dental restorative composition comprising a dentally acceptable polymerizable or polymerized bonding material and from about 10-90 percent by weight of a solid inorganic filler material, the improvement wherein said inorganic filler material is the finely divided ceramic hydroxylapatite according to claim 1.
Claim 34
Dependent Claim
15 words
A composition according to claim 30 wherein said dentally acceptable bonding material is polyacrylic acid.
Claim 35
Dependent Claim
22 words
A composition according to claim 30 wherein said dentally acceptable bonding material is the condensation product of bisphenol A and glycidyl methacrylate.
Claim 36
Dependent Claim
44 words
In a dental restorative composition comprising a dentally acceptable polymerizable or polymerized bonding material and from about 10-90 percent by weight of a solid inorganic filler material, the improvement wherein said inorganic filler material is the finely divided ceramic hydroxylapatite according to claim 3.
Claim 37
Dependent Claim
44 words
In a dental restorative composition comprising a dentally acceptable polymerizable or polymerized bonding material and from about 10-90 percent by weight of a solid inorganic filler material, the improvement wherein said inorganic filler material is the finely divided biphasic ceramic according to claim 6.
Claim 38
Dependent Claim
15 words
A composition according to claim 34 wherein said dentally acceptable bonding material is polyacrylic acid.
Claim 39
Dependent Claim
22 words
A composition according to claim 34 wherein said dentally acceptable bonding material is the condensation product of bisphenol A and glycidyl methacrylate.
Claim 40
Dependent Claim
44 words
In a dental restorative composition comprising a dentally acceptable polymerizable or polymerized bonding material and from about 10-90 percent by weight of a solid inorganic filler material, the improvement wherein said inorganic filler material is the finely divided biphasic ceramic according to claim 7.
Claim 41
Dependent Claim
50 words
In a method for filling a cavity in a tooth which includes the step of filling said cavity with a dental restorative composition comprising a dentally acceptable polymerizable or polymerized bonding material and a solid inorganic filler, the improvement which comprises employing a dental restorative composition according to claim 30.
Claim 42
Dependent Claim
50 words
In a method for filling a cavity in a tooth which includes the step of filling said cavity with a dental restorative composition comprising a dentally acceptable polymerizable or polymerized bonding material and a solid inorganic filler, the improvement which comprises employing a dental restorative composition according to claim 34.
Claim 43
Dependent Claim
40 words
In a method for repairing a void in a living bone which includes the step of filling said void with a biocompatible ceramic material, the improvement which comprises employing as the biocompatible ceramic the polycrystalline ceramic according to claim 1.
Claim 44
Dependent Claim
40 words
In a method for repairing a void in a living bone which includes the step of filling said void with a biocompatible ceramic material, the improvement which comprises employing as the biocompatible ceramic the polycrystalline ceramic according to claim 6.
Claim 45
Dependent Claim
34 words
In a method for prosthetically reconstructing a defective living bone which includes the step of surgically implanting an artificial bone prosthesis, the improvement which comprises implanting an artificial bone prosthesis according to claim 5.
Claim 46
Dependent Claim
34 words
In a method for prosthetically reconstructing a defective living bone which includes the step of surgically implanting an artificial bone prosthesis, the improvement which comprises implanting an artificial bone prosthesis according to claim 9.
References Cited (Backward Citations)
US3787900A
Cited
US3873327A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-07-03 | 1982-01-02 | 1982-07-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-07-03 | 1986-01-02 | 1986-07-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-07-03 | 1990-01-02 | 1990-07-04 | $7700.00 | Window Closed / Lapsed |