A study by Metzger, et al tested the use of ultraviolet (UV) light on root canal walls as a complementary method for disinfection following use of sodium hypochlorite (NaOCl). NaOCl alone does not achieve effective disinfection in many cases. The study involved extracted teeth, which were infected with Enterococcus faecalis for 48 hours. After nonattached bacteria were washed away, the attached bacteria that remained were subjected to disinfection with 5% NaOCl alone and 5% NaOCl followed by exposure to UV light. The root canals were then tested for remaining viable bacteria, after which the canals were obturated and tested again after 14 days. The study found that with the use of NaOCl alone, only 47% of the cases achieved negative cultures. When NaOCl use was followed by UV light, 96% of cases achieved negative cultures, and this status was maintained after 14 days. The study authors conclude that illumination of root canals with UV light may be an effective supplementary method for achieving immediate disinfection of infected root canals.
(Source: Oral Surg Oral Med Oral Pathol Oral Radiol Endod, 2007, Volume 104, Number 3)
