Photodynamic Therapy Targets Root Canal Microorganism
Enterococcus faecalis inactivated after root canals sensitized with methylene blue
THURSDAY, Dec. 27 (HealthDay News) -- Photodynamic therapy can inactivate Enterococcus faecalis in experimentally infected root canals of extracted teeth after their sensitization with methylene blue, according to a report published in the December issue of Lasers in Surgery and Medicine.
In a model of root canal infection, Federico Foschi, D.D.S., Ph.D., of The Forsyth Institute in Boston, and colleagues prepared 64 root canal specimens from extracted, single-rooted teeth, inoculated them with E. faecalis, and incubated them with methylene blue for five minutes followed by exposure to light from a diode laser.
The researchers found that photodynamic therapy reduced E. faecalis viability by 77.5 percent and that methylene blue alone and light alone reduced bacterial viability by 19.5 percent and 40.5 percent, respectively.
"Different bacteria are involved in endodontic failures that may present different susceptibility to photodynamic therapy," the authors state. "Therefore, further studies with multi-species root canal infections will determine the optimum methylene blue concentration and light parameters to maximize bacterial killing, which, together with standard treatment, would minimize the risk of endodontic failure."