Tue-TFI-23: Coating of Ti-6Al-4V alloy with pure titanium ﬁlm by sputter-deposition for improving biocompatibility T. Sonoda,1 T. Saito,1 A. Watazu,1 K. Katou,1 T. Yamda,1 and T. Asahina1 1 National Institute of Advanced Industrial cience and Technology(AIST) Ti-6Al-4V alloy attracting attention as a biomaterial features excellent mechanical properties and corrosion re- sistance, and super plasticity, so enables the forming of denture bases of complicated shapes. However, this alloy contains aluminum and vanadium liable to do serious harm to human bodies, so actual use will require prevention of direct contact with biological tissues. On the other hand, pure titanium has been utilized as biomaterials in den- tal or orthopedic ﬁeld, and its prostheses or implants exhibit excellent biocompatibility. In this study, therefore, in order to improve the biocompatibility of Ti-6Al-4V alloy, coating of the alloy substrates with pure titanium ﬁlms by magnetron DC sputtering in Ar gas was examined, because the pure titanium barrier layer prevents such harmful substances from leaching out to biological tissues. Furthermore the effects of the pure titanium barrier layer on the cytocompatibility of the titanium alloy were investigated. Under visual observation, the obtained pure titanium ﬁlm appeared to be uniform and adhesive. Under SEM, the surface of the deposited pure titanium ﬁlm was observed to consist of ﬁne particles accumulating and aggregating. According to AES in-depth proﬁles of Ti and Al for the deposited titanium ﬁlm and Ti-6Al-4V alloy substrate, it was conﬁrmed that no aluminum atoms diffused to the ﬁlm surface from the alloy substrate. Based on the results of the in-vitro cytotoxicity test, it was found that the viability, i.e., the ratio of the number of living cells to the sum of the number of living cells and that of dead cells was higher for the titanium ﬁlm than for the alloy. Therefore the deposited pure titanium ﬁlm exhibited better cytocompatibility than the Ti-6Al-4V alloy, concluding that the biocompatibility of the alloy was improved by coating with the pure titanium ﬁlm.