comparison of antibacterial effect of photoactivated laser with chlorhexidine 2% and sodium hypochlorite 2.5% in infection root canal with Entrococcus faecalis

Abstract

Introduction: Bacteria which infiltrate into root canal system, invade dentinal tubules and might cause permanent infections in root canals in case disinfecting solutions could not penetrate into these tubules. Furthermore, bacteria such as Entrococcus faecalis coluld produce intra- and extra-radicular biofilms which are difficult to eliminate. Because of adjustable penetration depth of laser therapy, better access to complex portions of root canal system would take place by employing lasers. Therefore, this study was aimed to compare the ability of light activated low power laser in elimination of Entrococcus faecalis from root canal system with routine disinfecting solutions (chlorhexidine 2% and sodium hypochlorite 2.5%). Materials and methods: Canals of sixty upper central incisors were infected by Entrococcus faecalis and then the bacteria were incubated for 24 hours. Samples were divided into four groups randomly. In first group, any action was not perfomed and this was considered as control. In the second group, laser therapy with 1 watt power of Diode laser for 120 seconds was taken place. In groups three and four, canals were irrigated by chlorhexidine 2% and sodium hypochlorite 2.5% solutions, respectively. Results: Growth inhibition ability of all experimental gropus was significantly beetr than control group (P<0.05). There was not a siginificant difference between the effect of light-activated laser and chlorhexidine 2% irrigation (P>0.05). The effect of sodium hypochlorite irrigation was better than light-activated laser (P<0.05). The effect of sodium hypochlorite in 10-2 and average dilutions was better than chlorhexidine 2%. In comparison to control group, the remained bacteria in laser, chlorhexidine, and sodium hypochlorite was 4.56%, 2.93%, and 0.82% respectively. Conclusions: Based on the findings of this in-vitro study, photo-dynamic therapy was effective in reducing the conut of Entrococcus faecalis in comparion to control group but this effect was less than chlorhexidine 2% and sodium hypochlorite 2.5% irrigations