Electrochemical Treatment of Contaminated Titanium Surfaces in Vitro: An Approach for Implant Surface Decontamination

Bacterial contamination on titanium implants can cause inflammation and eventually implant failure. Currently used methods for decontamination of implants have demonstrated limited success. Metal surfaces can be disinfected electrochemically. However, the effect of electrochemical treatments on biofilm-contaminated titanium is largely unknown. We hypothesized that electrochemical treatments are able to safely remove organic contamination and bacteria from titanium implants without altering their surfaces. This study was designed to assess the electrochemical properties of bacteria-contaminated surfaces in order to develop new treatments to clean titanium. Surface morphology, composition, bacterial load, and electrochemical properties of polished titanium discs were analyzed before and after biofilm contamination and subsequent decontamination with various electrochemical methods. The effect of the combination of the electrochemical with titanium brush cleaning was also evaluated. Results were then analyzed and compared to baseline readings (prior to contamination) using repeated measures ANOVA. Biofilm contamination increased the levels of carbon, nitrogen, and live bacteria on titanium surfaces while reducing their open circuit potential and corrosion resistance. Optimized electrochemical treatments with alternating current (-2.3 mA, + 22.5 μA) and voltages (1.8 V), were bactericidal and able to completely decontaminate saliva-contaminated titanium surfaces within 5 min while preserving surface integrity and histological quality of mammalian tissues. Furthermore, with the aid of mechanical brushing, the optimized electrochemical treatment was able to achieve complete decontamination of biofilm-contaminated Ti surfaces. The electrochemical treatment seems to be promising and well worth investigating for the clinical management of peri-implant infections.