Patent US5211833A successfully refreshed from Google Patents.
US5211833A
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US
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Method for coating implants and surgical devices made of titanium and titanium alloys
Assignee: Queen's University
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Filing: 1991-07-24
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Granted: 1993-05-18
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Expires: 2011-07-24
Abstract
Abstract A method for coating implantable medical devices, such as orthopaedic prostheses, with a dense, substantially non-porous oxide coating so as to minimize ion release therefrom, and the product of that process is described. The prosthesis is subjected to anodic electrolytic deposition in an alcoholic electrolyte containing alkali metal nitrate or nitric acid. In a preferred embodiment the anodically coated prosthesis is also coated with a bioactive layer of calcium phosphate.
Inventors
- 👤 Morteza Shirkhanzadeh
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 23:06
CPC Classifications
A; A61; A61F; A61F2/00; A61F2/02; A61F2/30; A61F2/30767; C; C25; C25D; C25D11/00; C25D11/02; C25D11/26; A61F2/3094; A61F2002/30929; A61F2310/00; A61F2310/00005; A61F2310/00011; A61F2310/00023; A61F2310/00035; A61F2310/00089; A61F2310/00389; A61F2310/00592; A61F2310/00598; A61F2310/00616; A61F2310/00796
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
101 words
A process for producing a protective, dense, non-porous and biocompatible oxide coating on a metal substrate selected from the group consisting of titanium, zirconium and alloys thereof, comprising anodically depositing said oxide coating by immersing a selected said substrate in an electrolyte comprising at least one of an alkali metal nitrate and nitric acid dissovled in an alcohol having the formula ROH where R is selected from an alkyl group having 1 to 4 carbon atoms, an aryl group and mixtures thereof, and passing a current through said electrolyte for a sufficient time to anodically deposit said coating on said substrate.
Claim 2
Dependent Claim
101 words
A process for producing a protective, dense, non-porous and biocompatible oxide coating on a metal substrate selected from the group consisting of titanium, zirconium and alloys thereof, comprising anodically depositing said oxide coating by immersing a selected said substrate in an electrolyte comprising at least one of an alkali metal nitrate and nitric acid dissovled in an alcohol having the formula ROH where R is selected from an alkyl group having 1 to 4 carbon atoms, an aryl group and mixtures thereof, and passing a current through said electrolyte for a sufficient time to anodically deposit said coating on said substrate.
Claim 3
Dependent Claim
16 words
The process of claim 1, wherein said alcohol is selected from methanol, ethanol and mixtures thereof.
Claim 4
Dependent Claim
15 words
The process of claim 1, wherein said alcohol contains less than 10% by volume water.
Claim 5
Dependent Claim
20 words
The process of claim 1, wherein said alkali metal nitrate is selected from sodium nitrate, potassium nitrate and mixtures thereof.
Claim 6
Dependent Claim
16 words
The process of claim 1, wherein an anodizing voltage of less than 20 volts is applied.
Claim 7
Dependent Claim
20 words
The process of claim 1, wherein the anodizing current is from about 2 to about 20 mA per square centimeter.
Claim 8
Dependent Claim
39 words
The process of claim 1, wherein the concentration of said at least one of alkali metal nitrate and nitric acid is adjusted below the saturation level thereof so as to provide a minimum current density of 2 mA/sq cm.
Claim 9
Dependent Claim
30 words
The process of claim 1, wherein the anodizing process is continued for a sufficient time to form an oxide coating having a thickness from about 1 to about 40 microns.
Claim 10
Dependent Claim
22 words
A process according to claim 8, wherein the surface of the metal substrate is polished to a mirror finish prior to anodizing.
Claim 11
Dependent Claim
30 words
A process according to claim 8, wherein the said coated metal substrate is subjected to a heat treatment step at a temperature in the range of 300° to 800° C.
Claim 12
Dependent Claim
15 words
A process according to claim 10, wherein said heat treatment is effected under vacuum conditions.
Claim 13
Dependent Claim
16 words
A process according to claim 10, wherein said heat treatment is effected in an oxygen atmosphere.
Claim 14
Dependent Claim
27 words
A process according to claim 1, including anodizing said coated metal substrate in a phosphoric acid bath under selected conditions so as to improve corrosion resistance thereof.
Claim 15
Dependent Claim
19 words
A process according to claim 1, including coating said coated metal substrate with a layer of bioactive calcium phosphate.
Claim 16
Dependent Claim
17 words
A process according to claim 14, wherein said bioactive calcium phosphate coating is applied by plasma spraying.
Claim 17
Dependent Claim
16 words
A process according to claim 14, wherein said bioactive calcium phosphate coating is applied by electrodeposition.
Claim 18
Dependent Claim
12 words
An oxide coated metal substrate made by the process of claim 1.
Claim 19
Dependent Claim
15 words
An oxide and calcium phosphate coated metal substrate made by the process of claim 14.
References Cited (Backward Citations)
JPH0282966A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-05-17 | 1996-11-16 | 1997-05-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-05-17 | 2000-11-16 | 2001-05-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-05-17 | 2004-11-16 | 2005-05-18 | $7700.00 | Window Closed / Lapsed |