Ex Vivo Assessment of Photodynamic Therapy in Achieving Microbial Reduction.

: The study was to assess the effects of photodynamic therapy (PDT) on root canals contaminated by Enterococcus faecalis (E. faecalis). PDT was performed with 0.005% methylene blue dye and with a low-intensity red emission laser. Microbiological samples were collected before, immediately and 72 hours after instrumentation. Although PDT performed with the chosen light parameters promoted additional microbial reduction, this therapy did not achieve a statistically significant reduction of E. faecalis.