Titanium Nitride (TiN)

Titanium nitride (TiN) coating is designed as a biocompatible ceramic layer used on the bearing surfaces of certain implants to form a hard bearing surface for articulation with ultra-high molecular weight polyethylene (UHMWPE).

As a ceramic surface,TiN coating is designed to exhibit hardness four times greater than that of cobalt chrome alloys (2400HV for TiN compared to 650HV for CoCr) and low surface roughness (Ra<0.05µm). It has enhanced wettability characteristics with synovial fluids and a low coefficient of friction, minimising polyethylene wear and making it ideal as a bearing surface.

The hard coating also provides protection in the presence of third body wear such as polymeric or cement debris. Its surface scratch resistance prevents implant damage at excessive contact loads. Even on scratch formation the height of the scratch lip is extremely low, resulting in a substantial reduction in wear as opposed to scratched cobalt chrome implants. TiN ceramic coatings have shown up to 98% reduction in wear against polyethylene in hip simulator studies.

TiN surface coatings have also been shown to provide a solution to metal allergy, protecting patients from adverse allergic reactions. The ceramic layer reduces release of metal ions into the patient's joint space and minimises bacterial proliferation. Especially for nickel sensitive patients, TiN provides a simple, effective and proven implant solution.

The addition of a TiN coating therefore enables the mechanical properties of the underlying surface to be retained whilst optimizing the bearing surface performance, providing a low wear solution and allowing for optimized wear characteristics