A comparison of the antibacterial activity of the two methods of photodynamic therapy (using diode laser 810 nm and LED lamp 630 nm) against Enterococcus faecalis in extracted human anterior teeth

• PDT serves as a good option to maximize root canal disinfection and as an adjunct technique in endodontic treatments.
• PDT with diode laser 810 nm could evidently decrease amount of Enterococcus faecalis in root canals.
• Significant reduction in Enterococcus faecalis was observed after PDT with LED lamp.
• LED lamps may also be a good option for other types of bacteria in charge of endodontic pathologies.

BackgroundFailure of endodontic treatment is usually due to an inadequate disinfection of the root canal system. Enterococcus faecalis has been widely used as a valuable microbiological marker for in-vitro studies because of its ability to colonize in a biofilm like style in root canals, invading dentinal tubules and resistance to some endodontic treatments.The aim of this study was to investigate the antibacterial effects of two methods of photodynamic therapy using a light emitting diode lamp (LED lamp, 630 nm) and a diode laser (810 nm) on E. faecalis biofilms in anterior extracted human teeth.MethodsFifty six single-rooted extracted teeth were used in this study. After routine root canal cleansing, shaping and sterilization, the teeth were incubated with E. faecalis for a period of two weeks. Teeth were then divided into two experimental groups (nu = 23) and two control groups (nu = 5). Teeth in one experimental group were exposed to a diode laser (810 nm), and in the other group samples were exposed to a LED lamp (630 nm). Intracanal bacterial sampling was done, and bacterial survival rate was then evaluated for each group.ResultsThe Colony Forming Unit (CFU) in LED group (log 10 CFUs = 4.88 ± 0.82) was significantly lower than the laser group (log CFUs = 5.49 ± 0.71) (p value = 0.021). CFUs in positive control group (Log 10 CFUs = 10.96 ± 0.44) were significantly higher than the treatment group (p ˂ 0.001). No bacterial colony was found in negative control group.ConclusionThe results of this research show that photodynamic therapy could be an effective supplement in root canal disinfection. PDT using LED lamp was more effective than diode laser 810 nm in reducing CFUs of E. faecalis in human teeth.