Objective: The study was designed to test application of ultraviolet light to root canal walls, as a mean of complementary immediate disinfection after the use of sodium hypochlorite.
Study design: Root canals were infected ex vivo with Enterococcus faecalis for 48 hours. Non-attached bacteria were washed away, and the remaining attached bacteria were subjected to disinfection, with 5% sodium hypochlorite alone or followed by exposure to ultraviolet light (254 nm, 300 mJ/cm(2)). Root canals were then tested for remaining viable bacteria. Canals were obturated and tested again after 14 days.
Results: Sodium hypochlorite alone achieved negative cultures in only 47% of the cases, but 96% was achieved with sodium hypochlorite followed by ultraviolet light (P < .001). This status was also maintained after 14 days.
Conclusions: Illumination of root canals with ultraviolet light may be an effective supplementary means to achieve immediate disinfection of infected root canals.