Titanium Nitride (TiN)

Contents:

  1. Coating Procedure
  2. Sterilization
  3. Bacterial Adhesion
  4. Biocompatibility
  5. Fidelity
  6. References

Titanium Nitride (TiN) is a bio-compatible coating which is typically used to coat the surface of bone implants. It has been found to be both non-cytotoxic, resistant to bacterial adhesion, and more wear-resistant when compared to other titanium implant surfaces.

Coating Procedure


TiN is attached to a substrate by physical vapor deposition (PVD) of pure titanium and nitrogen gas to create a thin surface layer (3-10micrometers) of TiN coating.

Sterilization


Both hydrogen peroxide and sodium hypochlorite (bleach) will destroy the TiN coating, and should be avoided for sterilization. Any sterilization technique that involves heating (such as autoclaves, boiling, etc.) will also permanently damage the coating and should not be used. DangerousThings provides 0.67mL ampoule of ChloraPrep which contains 2% chlorhexidine gluconate (CHG) and 70% isopropyl alcohol (IPA) and may be used to sterilize anything with a TiN coating prior to implantation.

Bacterial Adhesion


When compared to uncoated (titanium) implants, bacterial adhesion has shown to decrease by use of a TiN surface coating. Bacterial adhesion is a major source of implant failure and rejection[4]. The reduced bacterial adhesion is due to a difference in surface composition, as the roughness of the TiN coating when compared to the titanium-only implant were similar.

Biocompatibility


TiN, along with the titanium alloys TiON and TiAlN were analyzed in a solution similar to human blood, and were found to be non-cytotoxic. [6]

Fidelity


TiN coated implants show decreased polyethylene and metal wear when compared with other implant materials. [3] When compared to cobalt chromium in a long-term joint simulation, the wear on the TiN coating was an order of magnitude lower than its counterpart. [5]

For further information, please refer to the Wikipedia article and Material Safety Data Sheet for TiN.

References


[1] Improving Performance of Implants
[2] DangerousThings Website
[3] Wear analysis of a retrieved hip implant with titanium nitride coating
[4] Bacterial Adhesion on Titanium Nitride-coated and Uncoated Implants: An In Vivo Human Study
[5] Titanium Nitride Ceramic Film Against Polyethylene: A 48 Million Cycle Wear Test.
[6] A comparative study of titanium nitride (TiN), titanium oxy nitride (TiON) and titanium aluminum nitride (TiAlN), as surface coatings for bio implants