Comparative Efficacy of Three Single-File Reciprocating Systems in Reducing Intracanal Enterococcus faecalis Biofilms.

OBJECTIVES: Chemomechanical preparation is essential to disrupt endodontic biofilms and reduce microbial loads to levels compatible with periradicular tissue healing. This study aimed to compare the bacterial reduction efficacy of three reciprocating single-file systems-WaveOne Gold, One Reci, and R-Motion-against Enterococcus faecalis in root canals. METHODS: Sixty-two human premolars were inoculated with E. faecalis and instrumented using one of the three reciprocating systems. Intracanal bacterial loads were quantified via colony-forming units (CFUs) before and after chemomechanical preparation. Additionally, five specimens from each group were analyzed via scanning electron microscopy (SEM) to qualitatively assess biofilm disruption. Data were analyzed using one-way analysis of variance (ANOVA) with the significance level set at p < 0.05. RESULTS: All three reciprocating systems demonstrated a comparable reduction in intracanal microbial loads (p > 0.05) from a mean baseline of approximately 6.78 log₁₀ CFU. The mean log-based relative percentage reductions percentage reductions ranged from 36.8% (WaveOne Gold) to 40.0% (R-Motion). SEM analysis revealed the persistence of residual biofilm across all experimental groups. CONCLUSIONS: Despite variations in instrument design and metallurgy, the three evaluated reciprocating systems demonstrated comparable efficacy in reducing intracanal E. faecalis populations.