Abstract: Objective To study the antibacterial properties of Fe3＋-doped TiO2 film against Streptococcus mutans. Methods Pure TiO2 film and Fe3＋-doped TiO2 films were prepared by a sol-gel technique with dip coating method on Co-Cr alloy. With the cobalt-chromium alloy serving as the control group, the antibacterial properties of pure TiO2 film and Fe3＋-doped TiO2 films against Streptococcus mutans were evaluated with sticking-membrane method under ultraviolet (UV), fluorescent light and in the darkness. The doping content of Fe3＋ was measured as the antibacterial property was at its best. Results Under different lighting conditions, the antibacterial effects of pure TiO2 film group and Fe3+-doped TiO2 film were statistically different compared with the control group (P<0.05).The Fe3＋-doped TiO2 film appeared good antibacterial activity with the n(Fe3+) /n(Ti) of 2% under UV and dark conditions, while n(Fe3+) /n(Ti) of 1.5% under fluorescent light. Conclusion The Fe3＋-doped TiO2 film has more active antibacterial property than the pure TiO2 film, and it may also have certain antibacterial activity in the darkness. The antibacterial activity can be controlled by adjusting the relative ratio of n(Fe3+) /n(Ti).

Key words: TiO2 film, sol-gel, Fe3＋-doped, antibacterial property