Antibacterial and Antibiofilm Efficacy of Antimicrobial Photodynamic Therapy Against Intracanal Enterococcus faecalis: An In Vitro Comparative Study with Traditional Endodontic Irrigation Solutions

Enterococcus faecalis (E. faecalis), an infecting microorganism of the root canals, is difficult to eliminate during endodontic therapy. In this study, the effect of root canal disinfection with sodium hypochlorite (NaOCl) and chlorhexidine (CHX) was evaluated on planktonic and biofilm forms of E. faecalis in comparison with antimicrobial photodynamic therapy (aPDT) as an alternative strategy for root canal disinfection.
In this study, E. faecalis (ATCC 29212) was used. The experimental procedures included aPDT with curcumin (CUR) and indocyanine green (ICG) as photosensitizers, irrigation with 5.25% NaOCl, 0.2% and 2.0% CHX solutions as traditional endodontic irrigating solutions, and the control group. The antibacterial and anti-biofilm potentials were assessed by counting the colony forming units and also using the crystal violet assay, respectively.
According to the results, E. faecalis biofilm was disrupted by 65.3%, 81.0% and 92.6% using 0.2% CHX, 2.0% CHX, and 5.25% NaOCl, respectively (P APDT has a high potential for elimination of E. faecalis and is almost equivalent to NaOCl and CHX. It can be used as an adjucnt to conventional endodontic irrigating solutions.