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

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.

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.

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.

Electrochemical treatments had a bactericidal effect on this multispecies subgingival in vitro biofilm model, being the reduction more effective than the oxidative treatment.