Even though titanium(Ti) and its alloys are the most used dental implant materials, there are some problems that Ti wears easily and interferes normal osteogenesis due to the metal ions. Ti coated with bioactive ceramics such as hydroxyapatite has also such problems as the exfoliation or resorption of the coated layer. Recent studies on implant materials have been proceeding to improve physical properties of the implant substrate and bio Compatibility of the implant surfaces.

The purpose of the present study was to examine the physical property and bone tissue compatibility of bioinert nitrides ion plated Ti. Button type specimens(l4mm in diameter, 2.32mm in height) for the abrasion test and cytotoxicity test and thread type implants(3.75mm in diameter, 6mm in length) for the animal experiments were made from Ti(grade 2) and 316LVM stainless steel. Ti specimens were ion plated with TiN, ZrN by the low temperature arc vapor deposition, and the depth profile of the TiN/Ti, ZrN/Ti ion plated surface was examined by Auger Electron Spectroscopy. Three kind of button type specimens of TiN/Ti, ZrN/Ti and Ti were used for abrasion test, and HEPAlClC7 cells and CCD cells were cultivated for 4 days with the specimens for cytotoxicity test. Thread type implants of TiN, ZrN/Ti, Ti, 316LVM were implanted on the femur of 6 adult dogs weighing l0kg-l3kg. Two dogs were sacrified for histological examination after 45 days and 90 days, and four dogs were sacrificed for the removal torque test of the implants after 90 days. The removal torque force was measured by Autograph (Shimadzu Co., AGS-l000D series, Japan). Abrasion resistance of TiN/Ti was the highest, and that of ZrN/Ti and Ti were Followed. The bioinert nitride ion plated Ti had much better abrasion resistance, compared with Ti. In the cytotoxicity test, the number of both cells were increased in all specimens, and there were no significant difference in cytotoxic reaction among all groups (p>0.1). In histological examination, 316LVM showed the soft tissue engagement in interface between the implant and bone, but the other materials after 45 days noted immature new bone formation in the medullary portion along the implant surface, and those after 90 days showed implant support by new bone formation in both the cortical and the medullary portion. The removal torque force of TiN/Ti showed significantly higher than that of Ti(p<0.05). The difference in removal torque force between TiN/Ti and ZrN/Ti was not significant (p>0.05), and that of 316LVM was lowest among all groups(p<0.05).

These results suggest that bioinert nitrides ion plated Ti can resolve the existing problems of Ti and bioactive ceramics, and it may be clinically applicable to human.