Biofilm forming capacity of Enterococcus faecalis on Gutta-percha points treated with four disinfectants using confocal scanning laser microscope: An in vitro study

BACKGROUND: The aim of this study was to evaluate and compare the in vitro biofilm forming capacity of Enterococcus faecalis on Gutta-percha points disinfected with four disinfectants. MATERIALS AND METHODS: A total of 50 Gutta-percha points used in this study were divided into four test groups based on disinfectant (5.25% sodium hypochlorite, 2% chlorhexidine gluconate, 20% neem, 13% benzalkonium chloride [BAK]), and one control group. The Gutta-percha points were initially treated with corresponding disinfectants followed by anaerobic incubation in Brain Heart Infusion broth suspended with human serum and E. faecalis strain for 14 days. After incubation, these Gutta-percha points were stained with Acridine Orange (Sigma – Aldrich Co., St. Louis, MO, USA) and 0.5 mm thick cross section samples were prepared. The biofilm thickness of E. faecalis was analyzed quantitatively using a confocal scanning laser microscope. Results statistically analyzed using analysis of variance. P < 0.05 was considered to be significant. RESULTS: Confocal scanning laser microscope showed reduced amount of E. faecalis biofilm on Gutta-percha points treated with BAK and sodium hypochlorite. Post-hoc (least square differences) test revealed that there is no statistically significant difference between BAK and sodium hypochlorite groups (P > 0.05). CONCLUSION: This study illustrates that the Gutta-percha points disinfected with sodium hypochlorite and BAK showed minimal biofilm growth on its surface.