In vitro evaluation of chemical decontamination of titanium discs

Peri-implant diseases are caused by bacterial biofilm colonizing implant surfaces. Prevention and management of peri-implant mucositis and peri-implantitis rely on effective biofilm removal. This study aimed to evaluate biofilm removal and cytocompatibility following chemo-mechanical surface decontamination of biofilm-coated titanium discs. Biofilm-coated (Streptococcus gordonii) discs, with either non-modified (smooth) or modified (rough) surfaces, were instrumented using a sterile gauze soaked in one out of four solutions: saline (NaCl), alkaline electrized water (AEW), citric acid (CA) or N-acetyl-l-cysteine (NAC). Non-contaminated, untreated titanium discs served as controls (C). Residual deposits (bacteria and gauze fibers) and cytocompatibility for osteoblast-like cells were evaluated using SEM and immunofluorescence. Cytotoxicity was assessed using WST-8 assay and immunofluorescence. All protocols were equally effective in removing bacteria from smooth surfaces, while AEW and CA were found to be superior at rough surfaces. AEW and NAC were superior in promoting cytocompatibility over NaCl. NAC and CA had a strong cytotoxic effect on osteoblast-like and fibroblast cells. In conclusion, AEW may be beneficial in the decontamination of implant surfaces, effectively removing bacterial biofilm and restoring cytocompatibility.