[Experimental study on biomaterials coated with titanium-nitride ceramic for orthopedics].

Ceramic has excellent properties. However, the brittleness of ceramic is one of the major problems. Coating ceramic on stronger substance materials may be one of the ways to overcome this problem. In this study, stainless steel (316L) coated with titanium nitride ceramic (TiN), produced by using a physical vapor deposition method, was investigated. The results indicated that although the yielding strength was decreased by exposing the material to 550 degrees C, the grain structure did not change. Stainless steel with 3.0 micron TiN coating demonstrated high resistance to bending stress and friction. In addition, this material displayed sufficient fatigue strength for an orthopaedic implant after 10(7) loading repetitions. Based on organ cultures and animal experiments, the biocompatibility of TiN coated stainless steel appeared to be superior to uncoated stainless steel. The TiN coating dissolved in H2O2 although it was stable to HNO3. In conclusion, titanium nitride ceramic coated stainless steel appears to be a promising material for implantation. However, further investigation is necessary for a long term results as an implant material.