An in vitro study on the efficacy of hydrogen peroxide mediated high-power photodynamic therapy affecting Enterococcus faecalis biofilm formation and dispersal.

Abstract

Biofilms are involved in failure of root canal treatment due to their high resistance to antimicrobial agents, which make their removal as a big challenge. The present study aims at utilizing hydrogen peroxide (HP) plus high frequency laser reinforced antimicrobial photodynamic therapy (a-PDT) as a complementary therapy against Enterococcus faecalis (E. faecalis) at planktonic and biofilm stages. E. faecalis at planktonic and biofilm stages was treated with the photosensitizer HP, followed by no irradiation or irradiation with a power of 2.5W (ʎ=980nm). The cell viability, anti-biofilm, anti-metabolic potential, and temperature changes were evaluated. The combination of HP and 980nm diode laser intensely boosted antibacterial and anti-biofilm efficacy compared with either component alone, affirming HP reinforcement as a bacteriostatic agent. The maximum effect on biofilm occurs in 5.25% sodium hypochlorite (NaOCl) group. During laser irradiations, the mean of temperature changes remains below 5.6°C. It could be concluded that the HP could improve anti-biofilm efficacy as a photosensitizer in a-PDT.