Methods: Sixty two single rooted human teeth were prepared and contaminated with E faecalis. The roots were divided into negative control (uninfected) (n=2), positive control (NSS) (n=10) and 5 experimental groups (n=10). The experimental groups were subjected to either PAD(13 to 15 μg/ml of tolonium chloride and laser light (633±2 nm) generated by diode laser) , 2.5% NaOCl, 2% CHX, 2.5% NaOCl followed by PAD and 2.0% CHX followed by PAD. After treatment, all roots were incubated for 24 hr. The canal contents were sampled with sterile paper points, and colony-forming units (CFU) were determined. Surface topography and biofilm formation after irrigation for 24 hr were analyzed by scanning electron microscopy (SEM).
Results: Treatment of root canals with PAD did not significantly reduce the number of e.faecalis. Irrigation with 2.5% NaOCl, 2% CHX caused a significant reduction of the bacteria (66.69% and 86.77%, respectively). Combination of PAD and either 2.5% NaOCl or 2% CHX irrigation did not improve the efficacy in E.faecalis elimination, compared to irrigation alone.
Conclusions: PAD treatment did not efficiently eliminate E.faecalis whereas 2.5% NaOCl and 2% CHX significantly reduced the bacterial load in the root canal.