Development of New Hydrogen-containing Tetrahydral Amorphous Carbon Thin Films using Cathodic Arc Plasma for Dental Implant

The purpose of this study is to improve the durability and bone-compatibility of DLC films for use in dental implants. We fabricated ta-C:H films on Ti plates by CA method using a graphite solid and a CH4 gas as a source for the DLC film, and investigated the CH4 gas flow ratio dependence of the current?voltage characteristics, film properties, and film structures during the ta-C:H formation. It was found that an increase in production of CHx ions leads to a decrease in the space impedance of the plasma with increasing CH4 gas flow, and to an increased substrate bias current. The ta-C:H films avoided hardness lowering and maintained the hardness of 48 GPa even for hydrogen content of 15.9 at.%. The ta-C:H film fabricated by the CA method was found to be much harder than the a-C:H film fabricated by the CVD method. Therefore, we can expect that ta-C:H films will exhibit good durability and improve the surface of the bone/dental implant. ID/IG ratio measured by Raman spectroscopy tended to decrease with increasing substrate bias voltage.