Conventional, Passive Ultrasonic Irrigation, Photodynamic Therapy Efficacy on Enterococcus faecalis

Objective:  This in vitro study aimed to investigate the effect of irrigation technique among conventional irrigation (CI), passive ultrasonic irrigation (PUI), and photodynamic therapy (PDT) on the amount of Enterococcus faecalis colonies. Method:  Root canals of twenty human extracted teeth with single straight canals were prepared with Mtwo file (VDW, Germany), sterilized, contaminated with E. faecalissuspension, and incubated for 18 hours. The teeth then randomly distributed into four experimental groups: group 1(NaOCl, EDTA, and CHX irrigation using 30-gauge syringe ), group 2 (NaOCl irrigation using PUI), group 3 (NaOCl irrigation using 30-gauge syringe + PDT), group 4 (NaOCl irrigation using 30-gauge syringe). Sample were taken before and after specific irrigation procedure for each group, plated, and incubated to determine the number colony-forming units. The data obtained were analyzed by using one-way analysis of variance and the post hoc LSD test. Result: Group 1 had the lowest colony-forming unit score, which was significantly different from the other group (p < 0.05). Group 3 was in the second place but no significantly higher bacterial reduction than group 2 and 4. Conclusion: It was not the irrigation technique, but the type of irrigant used that effect the amount of Enterococcus faecalis colonies in the root canal treatment. The combination of NaOCl, EDTA, and CHX proved to have the greatest bacterial reduction.