Chemical debridement of contaminated titanium surfaces: Anin vitrostudy

Abstract

Objective. To compare the efficacy of different chemical solutions when used for chemical debridement of biofilm contaminated titanium surfaces in an in-vitro experimental study. Materials and methods. Commercially pure titanium discs with a diameter of 6.2 mm and height of 2 mm, mirror-polished with a measured surface amplitude value S_A = 0.037 μm ± 0.009 were used as test-surfaces. A biofilm was simulated with multi-layers of Staphylococcus epidermidis ATCC359844 covering the entire titanium surface. The chemical agents tested were: 3% H₂O₂, 0.2% Chlorhexidine, 24% EDTA-gel, 3% H₂O₂ mixed with 1.6 g/L TiO₂ and sterile saline solution. The decontamination effect was evaluated by optical density analysis using spectrophotometry and with scanning electron microscopy (SEM) images of the remaining biofilm. Results. The suspensions of 3% H₂O₂ and 1.6 g/L TiO₂ or 3% H₂O₂ alone were the most effective in removing S. epidermidis biofilms (p < 0.05), whereas 0.2% chlorhexidine or 24% EDTA gel had no significant effects. SEM images of the remaining biofilms supported the quantitative results indicating the higher efficacy of 3% H₂O₂ and 1.6 g/L TiO₂ or 3% H₂O₂ alone. It also revealed that EDTA, despite a non-significant effect on reducing the amount of established biofilms, was able to alter the biofilm architecture, as demonstrated by increased interspaced regions. Conclusions. In this in vitro study the decontamination potential of a suspension of 3% H₂O₂ and 1.6 g/L TiO₂ or 3% H₂O₂ alone were encouraging. Whether such procedures would have a similar effect in vivo remains to be determined.