Fabrication of Antibacterial Titanium Implant Using Anodic Oxidation Technique

In the present study, we demonstrated that antibacterial titanium can be simply fabricated by anodic oxidation technique, which involves connecting the Ti to the anode and then applying a direct current through the electrolyte. The substrate was soaked in 100−mM NH4NO3, 100−mM (NH4)2SO4, and (NH4)3PO4aqueous solutions, after which a constant current of 50 mA cm-2 was galvanostatically applied for 30 min. The substrate was thereafter annealed at 723 K in air for 5 h, in order to improve the crystallinity. The XRD pattern showed the layer comprised TiO2 with anatase and/or rutile type structures. All the anodized substrate could degrade methylene blue solution under ultraviolet (UV) and visible light illuminations. Antibacterial activities of the treated substrates were estimated using Escherichia coli (E. coli). The anodized Ti substrate showed sufficient antibacterial activity under weak UV light illumination with the intensity of 100 μW cm-2. In conclusion, anodic oxidation is expected as one of the promising surface treatments, in order to improve the safety of Ti devices in human use.