Zeliha Uğur AYDIN, Taha ÖZYÜREK, Gülşah USLU, Neslihan Büşra KESKİN, Demet ERDONMEZ
Turkish Endodontic Journal - 2026;11(2):139-145
Purpose: This study aimed to evaluate the effectiveness of rotary VDW.ROTATE (ROTATE), HyFlex EDM (HEDM), and reciprocating Reciproc Blue (RPCB) nickel-titanium file systems in reducing bacterial load in root canals infected with Enterococcus faecalis (E. faecalis). Methods: Thirty-four mandibular premolar teeth canals were contaminated with E. faecalis for four weeks and prepared using file systems (ROTATE, HEDM, or RPCB; n=10). Four uncontaminated teeth served as a negative control. Bacterial load was quantified via the plate culture method. Scanning electron microscopy (SEM) was used to assess the impact of preparation on biofilm. Bacterial reduction was calculated, and data were analyzed using one-way ANOVA at a 5% significance level. Results: Before preparation, all contaminated samples exhibited bacterial growth with an average bacterial load of 7.26 log CFU. All file systems reduced intracanal bacterial load (p<0.05), with no significant differences between systems (p>0.05). SEM images revealed disrupted biofilm-like structures in all groups, but bacteria were not completely eliminated in any canal section. Apical sections exhibited more smear layer than coronal sections. Conclusion: Microbiological analysis and SEM images confirmed that none of the tested file systems completely eliminated E. faecalis from root canals. No significant differences in bacterial reduction were observed among the file systems.
