In Vitro Evaluation of Antimicrobial Effects of Endodontic Irrigants Containing Disodium Edetate and Chlorhexidine Gluconate, Octenidine Dihydrochloride, and Benzalkonium Bromide Against Intracanal Enterococcus faecalis

<b>Background/Objectives</b>: The objective of this in vitro study was to compare and evaluate the in vitro antimicrobial effectiveness of Endosal, Octenisolv, and Endoxal against intracanal <i>Enterococcus faecalis</i>. <b>Methods</b>: The study sample consisted of 84 extracted single-rooted human teeth, which were divided into seven groups (12 roots in each group): Group 1-Endoxal, Group 2-Octenisolv, Group 3-Endosal, Group 4-15% ethylenediaminetetraacetic acid (EDTA), Group 5-2% sodium hypochlorite (NaOCl), Group 6-0.9% sterile saline solution (NaCl), and one positive control group where no irrigant was used. The roots were sterilized within an autoclave for 30 min at 121 °C and then contaminated with <i>E. faecalis</i> bacteria, after instrumentation and removing the smear layer from canals. The root canals were irrigated using a side-vented needle, and then ISO size 40 H-file was used to obtain fine dentine chips. Aliquots taken from the canals were plated on blood agar broth and the plates were incubated for 36 h. <b>Results</b>: In this study, significant differences were observed between the antimicrobial activity of Endoxal, Octenisolv, Endosal, 2% NaOCl, and sterile saline solution. <b>Conclusions</b>: The compound irrigants Endosal, Endoxal, and a novel irrigant containing disodium edetate and octenidine, which were evaluated in this study, exhibited relatively good antimicrobial properties against <i>Enterococcus faecalis</i>. The use of Endosal, Octenisolv or Endoxal appears promising, yet their clinical efficacy remains to be confirmed through further studies.