IMPLANT SURFACE WITH INCREASED HYDROPHILICITY

• US 20090191507A1
• Filed: 01/26/2009
• Published: 07/30/2009
• Est. Priority Date: 01/28/2008
• Status: Active Grant

• Current Assignee: Biomet 3i LLC (Zimvie Incorporated)
• Original Assignee: Biomet 3i LLC (Zimvie Incorporated)
• Inventors: Charlton, Jacqueline K., Towse, Ross W., Mayfield, Robert L.
• Granted Patent: US 8,309,162 B2
• Time in Patent Office: Days
• US Class Current: 433/173
• CPC Class Codes: A61C 8/0012 characterised by the material or composition, e.g. ceramics, surface layer, metal alloy use of specific materials A61K6/00
• CPC Class Codes: A61C 8/0013 with a surface layer, coating
• CPC Class Codes: A61C 8/0022 Self-screwing A61C8/0028 takes precedence
• CPC Class Codes: A61C 8/005 Connecting devices for joining an upper structure with an implant member, e.g. spacers
• CPC Class Codes: A61C 8/006 with polygonal positional means, e.g. hexagonal or octagonal
• CPC Class Codes: A61K 6/802 comprising ceramics
• CPC Class Codes: A61K 6/84 comprising metals or alloys
• CPC Class Codes: A61L 2400/18 Modification of implant surfaces in order to improve biocompatibility, cell growth, fixation of biomolecules, e.g. plasma treatment
• CPC Class Codes: A61L 2430/12 for dental implants or prostheses
• CPC Class Codes: A61L 27/06 Titanium or titanium alloys
• CPC Class Codes: A61L 27/10 Ceramics or glasses
• CPC Class Codes: A61L 27/306 Other specific inorganic materials not covered by A61L27/303 - A61L27/32
• CPC Class Codes: A61L 27/32 Phosphorus-containing materials, e.g. apatite
• CPC Class Codes: A61L 27/50 Materials characterised by their function or physical properties , e.g. injectable or lubricating compositions, shape-memory materials, surface modified materials
• CPC Class Codes: C23F 1/30 for etching other metallic material

Abstract

A method of increasing the hydrophilicity of an implant to be implanted into living bone. The method comprises the act of depositing non-toxic salt residuals on the surface of the implant by exposing the surface to a solution including the non-toxic salts. The method further comprises the act of drying the implant.

Claims

1. A method of increasing the hydrophilicity of an implant to be implanted into living bone, the method comprising the acts of:

depositing non-toxic salt residuals on the surface of the implant by exposing the surface to a solution including the non-toxic salts; and

drying the implant.

2. The method of claim 1, wherein the implant is made of a metal selected from the group consisting of tantalum, cobalt, chromium, titanium, stainless steel, or alloys thereof.

3. The method of claim 1, wherein the implant is made from a material including ceramic.

4. The method of claim 1, wherein the non-toxic salt is selected from the group consisting of sodium chloride, potassium chloride, calcium chloride, sodium lactate, and combinations thereof.

5. The method of claim 1, wherein the solution is selected from the group consisting of physiological saline solution and lactated Ringer'"'"'s solution.

6. A method of forming an implant to be implanted into living bone, the method comprising the acts of:

roughening at least a portion of the implant surface to form a roughened surface; and

increasing the hydrophilicity of the roughened surface by depositing non-toxic salt residuals on the roughened surface by exposing the roughened surface to a solution including the non-toxic salt.

7. The method of claim 6, wherein the implant is made of titanium or titanium alloy and the act of roughening the implant surface comprises:

removing a native oxide layer from the implant surface; and

acid etching the resulting surface.

8. The method of claim 6, wherein the act of roughening the implant surface creates irregularities having peak-to-valley heights not greater than about 20 microns.

9. The method of claim 6, wherein the non-toxic salt is selected from the group consisting of sodium chloride, potassium chloride, calcium chloride, sodium lactate, and combinations thereof.

10. The method of claim 6, wherein the solution is selected from the group consisting of physiological saline solution and lactated Ringer'"'"'s solution.

11. The method of claim 6, further comprising depositing discrete nanoparticles on the roughened surface by exposing the roughened surface to a solution including the nanoparticles, the nanoparticles comprising a material having a property that promotes osseointegration.

12. The method of claim 6, wherein a contact angle formed by a deionized water droplet on the surface of the implant ranges from about 5°

to about 65°

.

13. A method of forming a dental implant made of titanium or titanium alloy, the method comprising the acts of:

removing a native oxide layer from a threaded bottom portion of the dental implant;

acid etching the threaded bottom portion to form a roughened surface having an array of microscale irregularities having peak-to-valley heights not greater than about 20 microns;

depositing discrete hydroxyapatite nanocrystals on the roughened surface by exposure to a solution comprising 2-methoxyethanol solvent and the hydroxyapatite nanocrystals; and

depositing salt residuals on the roughened surface by exposure to a solution comprising non-toxic salts, wherein the salt residuals increase the hydrophilicity of the implant surface.

14. The method of claim 13, wherein the non-toxic salt is selected from the group consisting of sodium chloride, potassium chloride, calcium chloride, sodium lactate, and combinations thereof.

15. The method of claim 13, wherein the solution is selected from the group consisting of physiological saline solution and lactated Ringer'"'"'s solution.

16. The method of claim 13, wherein the act of depositing salt residuals further comprises drying the implant.

17. The method of claim 13, further comprising sterilizing the implant using gamma sterilization.

18. A dental implant comprising:

a head portion having a non-rotational feature;

a lowermost end opposing the head portion; and

a threaded bottom portion for engaging bone between the head portion and the lowermost end, the threaded bottom portion having a roughened surface with an array of microscale irregularities having peak-to-valley heights not greater than about 20 microns, the threaded bottom portion further including discrete nanoparticles located on the roughened surface, the nanoparticles including hydroxyapatite nanocrystals, the threaded bottom portion further including salt residuals deposited thereon.

19. The implant of claim 18, wherein the implant is made of a metal selected from the group consisting of titanium and titanium alloys.

20. The implant of claim 18, wherein the hydroxyapatite nanocrystals are on the order of about 20 nanometers to about 100 nanometers.

21. The implant of claim 18, wherein a contact angle formed by a deionized water droplet on the surface of the implant ranges from about 5°

to about 65°

.

22. A method of increasing the hydrophilicity of an implant to be implanted into living bone, the method comprising the acts of:

depositing non-toxic salt residuals on the surface of the implant by immersing at least a portion of the implant in a solution including sodium chloride, potassium chloride, calcium chloride, sodium lactate, or combinations thereof; and

drying the implant,

wherein the contact angle formed by a deionized water droplet on the surface of the implant ranges from about 5°

to about 65°

.

23. The method of claim 22, wherein the non-toxic salt residual is sodium lactate.

24. The method of claim 23, wherein the solution is physiological saline solution or lactated Ringer'"'"'s solution.

25. The method of claim 22 further comprising rinsing the implant prior to the act of drying the implant.

26. A method of forming an implant to be implanted into living bone, the method comprising the acts of:

grit blasting at least a portion of the implant surface with a grit blast media;

removing residual grit blast media;

roughening the grit blasted portion of the implant surface to form a roughened surface;

depositing discrete hydroxyapatite nanocrystals on the roughened surface; and

optionally increasing the hydrophilicity of the roughened surface by depositing non-toxic salt residuals on the roughened surface by exposing the roughened surface to a solution including the non-toxic salt.

27. The method of claim 26, wherein the grit blast media is a resorbable grit blast media.

28. The method of claim 27, wherein the resorbable grit blast media includes calcium phosphate.

29. The method of claim 26, wherein the act of removing residual grit blast media includes exposing the grit blasted portion of the implant surface to nitric acid.

30. The method of claim 26 further comprising, prior to the act of roughening the grit blasted portion of the implant surface, exposing the grit blasted portion of the implant surface to a first acid solution.

31. The method of claim 30, wherein the first acid solution includes hydrofluoric acid.