US5039546A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fluoride treatment of hydroxyapatite coated metal implants
Assignee: Ceramedical Inc
•
Filing: 1990-02-05
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Granted: 1991-08-13
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Expires: 2010-02-05
Abstract
Abstract A method for decreasing the dissolution rate of a hydroxyapatite coating or other calcium phosphate coating formed on a metal substrate by treating the coated metal substrate in a fluoride ion containing solution. The effective reagents for fluoride treatment can be any solution which supplies fluoride ion with the suitable pH of the solution being 3 or higher, preferably 5 or higher. The treatment enhances the stability of the coating strength.
Inventors
- 👤 Harvey Chung
- 👤 Sung-Tsuen Liu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 10:28
CPC Classifications
A; A61; A61C; A61C8/00; A61C8/0012; A61L; A61L27/00; A61L27/28; A61L27/30; A61L27/32; A61F; A61F2310/00; A61F2310/00389; A61F2310/00592; A61F2310/00796
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
59 words
A method for improving the stability of the coating strength and decreasing the biodegradation rate of a calcium phosphate based material coating formed on a metal substrate comprising the step of immersing the metal substrate in a fluoride ion containing solution for a time period necessary to convert the metal substrate coating to one containing less soluble fluoride compounds.
Claim 2
Independent Claim
59 words
A method for improving the stability of the coating strength and decreasing the biodegradation rate of a calcium phosphate based material coating formed on a metal substrate comprising the step of immersing the metal substrate in a fluoride ion containing solution for a time period necessary to convert the metal substrate coating to one containing less soluble fluoride compounds.
Claim 3
Dependent Claim
31 words
The method of claim 1 wherein said fluoride ion containing solution is selected from the group consisting of lithium fluoride, cesium fluoride, sodium fluoride, potassium fluoride, ammonium fluoride and stannous fluoride.
Claim 4
Dependent Claim
18 words
The method of claim 2 wherein said fluoride ion containing solution has a pH value greater than 3.
Claim 5
Dependent Claim
19 words
The method of claim 2 wherein the fluoride ion containing solution has a pH value of 5 or higher.
Claim 6
Dependent Claim
23 words
The method of claim 1 wherein the concentration of the fluoride ion in the fluoride ion containing solution ranges from 0.001% to 5%.
Claim 7
Dependent Claim
10 words
The method of claim 1 where said coating comprises hydroxyapatite.
Claim 8
Dependent Claim
20 words
The method of claim 1 further including the steps of washing the substrate after immersion and thereafter drying the substrate.
Claim 9
Dependent Claim
10 words
The method of claim 1 wherein said coating comprises apatites.
References Cited (Backward Citations)
US4687675A
Cited
US4746532A
Cited
US4795475A
Cited
US4801300A
Cited
US4847163A
Cited
US4871578A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-08-12 | 1995-02-11 | 1995-08-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-08-12 | 1999-02-11 | 1999-08-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-08-12 | 2003-02-11 | 2003-08-13 | $7700.00 | Window Closed / Lapsed |