Reverse transcription quantitative polymerase chain reaction-based comparative analysis of the antibacterial activity...

This study evaluated the antibacterial efficacy against Enterococcus faecalis (E. faecalis) biofilm of three irrigants combined with three irrigation activation protocols.

One hundred standardized and sterilized single-rooted human teeth were inoculated with E. faecalis for 21 days and randomly assigned to three main groups based on the irrigant used, namely, NaOCl, Dual Rinse-HEDP, and Chitosan (CS) (n = 30 each). Each group was then further divided into three subgroups (n = 10) according to the activation method employed, namely, standard needle irrigation (SNI), passive ultrasonic irrigation (PUI), and sonic activation (SA). Reverse transcription quantitative polymerase chain reaction (RT-qPCR) was used to analyze bacterial reduction. The results were analyzed using two-way ANOVA (P < 0.05).

As compared with the other irrigation solutions, antibacterial activity was highest for NaOCl (P = 0.009). Regarding activation methods, CS had greater efficacy when combined with SA, whereas Dual Rinse-HEDP showed no significant difference across activation protocols. NaOCl was the most effective irrigant overall, particularly when used with SNI and PUI.

NaOCl remains the gold standard for E. faecalis reduction. However, the antibacterial performance of CS can be significantly improved with sonic activation. Dual Rinse-HEDP maintains a consistent but limited antibacterial effect regardless of activation technique.