Electrochemical decontamination of titanium dental implants. An in vitro biofilm model study

Abstract

Objectives: The objective of this study is to study the effect of electrochemical treatment on biofilms developed on titanium dental implants, using a six-species in vitro model simulating subgingival oral biofilms. Materials and Methods: Direct electrical current (DC) of 0.75 V, 1.5 V, and 3 V (anodic polarization, oxidation processes) and of −0.75 V, −1.5 V, and -3 V (cathodic polarization, reduction processes) was applied between the working and the reference electrodes for 5 min on titanium dental implants, which have been previously inoculated with a multispecies biofilm. This electrical application consisted of a three-electrode system where the implant was the working electrode, a platinum mesh was the counter electrode, and an Ag/AgCl electrode was the reference. The effect of the electrical application on the biofilm structure and bacterial composition was evaluated by scanning electron microscopy and quantitative polymerase chain reaction. A generalized linear model was applied to study the bactericidal effect of the proposed treatment. Results: The electrochemical construct at 3 V and −3 V settings significantly reduced total bacterial counts (p <.05) from 3.15 × 106 to 1.85 × 105 and 2.92 × 104 live bacteria/mL, respectively. Fusobacterium nucleatum was the most affected species in terms of reduction in concentration. The 0.75 V and −0.75 V treatments had no effect on the biofilm. Conclusion: Electrochemical treatments had a bactericidal effect on this multispecies subgingival in vitro biofilm model, being the reduction more effective than the oxidative treatment.