Purpose: To compare the efficacy of EDDY, XP-Endo Finisher R (XPFR), and EndoUltra in removing Enterococcus faecalis (E. faecalis) from oval root canals with standard needle irrigation (SNI).
Methods: A total of 72 teeth with single-rooted and single oval-shaped root canals were selected. Teeth were sterilized in an autoclave, infected with E. faecalis, and inoculated in an incubator at 37°C for 7 days. Four teeth were processed for scanning electron microscopy analysis to control biofilm formation. The remaining 68 teeth were prepared with Reciproc Blue 25.08 and 40.06 files and then divided into four groups according to the irrigation activation techniques used: EDDY, EndoUltra, XPFR, and SNI (n = 17). Before (S1) and after (S2) irrigation techniques, the bacterial samples were taken from the root canals and colony-forming units (CFUs) were counted and calculated (CFU/mL). The data were statistically analyzed using the Shapiro–Wilk, Kruskal–Wallis, and Wilcoxon tests (p = 0.05).
Results: It was observed that CFU counts decreased significantly from S1 to S2 (p< 0.05). However, there was no significant difference among the irrigation activation techniques in terms of removing E. faecalis (p> 0.05).
Conclusion: The efficiency of EDDY, EndoUltra, XPFR, and SNI in the removal of E. faecalis was similar.