Implant surface with increased hydrophilicity

• US 8,852,672 B2
• Filed: 10/10/2012
• Issued: 10/07/2014
• 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., Mayfield, Robert L., Towse, Ross W.
• Primary Examiner(s): Feely, Michael J
• Application Number:
  US13/648,837
• Publication Number:
  US 20130037516A1
• Time in Patent Office: 727 Days
• Field of Search: 427/2.24, 427/2.25, 427/2.26, 427/2.27, 433/201.1
• US Class Current: 427/2.27
• 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 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 sodium lactate salt residuals on the roughened surface by exposing the roughened surface to a solution including the non-toxic sodium lactate salt.

2. The method of claim 1, 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.

3. The method of claim 2, wherein the implant is a dental implant including 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 native oxide being removed from a threaded bottom portion of the implant.

4. The method of claim 1, wherein the act of roughening the implant surface creates irregularities having peak-to-valley heights not greater than about 20 microns.

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. The method of claim 1, further comprising, prior to the act of depositing non-toxic sodium lactate salt residuals, 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.

7. The method of claim 6, wherein the nanoparticles are hydroxyapatite nanocrystals and the solution including the nanoparticles is 2-methoxyethanol solvent.

8. The method of claim 7, wherein the hydroxyapatite nanocrystals are on the order of about 20 nanometers to about 100 nanometers.

9. The method of claim 1, wherein a contact angle formed by a deionized water droplet on the surface of the implant ranges from about 5°

to about 65°

.

10. The method of claim 1, further comprising sterilizing the implant using gamma sterilization.

11. The method of claim 1, further comprising, prior to the act of roughening, grit blasting at least a portion of the implant surface with a grit blast media.

12. The method of claim 11, wherein the grit blast media is a resorbable grit blast media.

13. The method of claim 12, wherein the resorbable grit blast media includes calcium phosphate.

14. The method of claim 13, further comprising removing residual grit blast media by exposing the grit blasted portion of the implant surface to nitric acid.

15. 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 discrete non-toxic salt residuals on the roughened surface by exposing the roughened surface to a solution including the non-toxic salt, wherein the non-toxic salt includes sodium lactate.

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