In vitro comparative efficacy of two pulse widths of SWEEPS for elimination of Enterococcus faecalis biofilm from the root canals

Aim: This study aimed to compare the efficacy of two pulse widths of the shock wave enhanced emission photoacoustic streaming (SWEEPS) for elimination of Enterococcus faecalis (E. faecalis) biofilm from the root canals.

Materials and Methods: This in vitro experimental study was conducted on single-rooted single-canal extracted teeth. After cleaning and shaping and sterilization of root canals, they were inoculated with E. faecalis and were randomly assigned to 4 experimental groups (n=8) of (I) SWEEPS with ultra-short pulse (USP) mode and sodium hypochlorite (NaOCl) irrigation, (II) SWEEPS with super-short pulse (SSP) mode and NaOCl irrigation, (III) SWEEPS with USP mode and saline irrigation, and (IV) SWEEPS with SSP mode and saline irrigation, and 3 control groups (n=2) of bacterial inoculation with no disinfection (positive control), bacterial inoculation and disinfection without laser irradiation (negative control), and sterilization alone with no bacterial inoculation. Dentin chips were collected from the root canal walls, and E. faecalis colonies were counted after culture, and statistically analyzed by the Kruskal-Wallis and Dunnett tests (alpha=0.05).

Results: All experimental groups showed significantly lower colony count than the positive control group (P<0.05). Among the experimental groups, the highest reduction in colony count occurred in the USP-NaOCl, followed by the USP-saline, with no significant difference with the negative control group. The smallest reduction in colony count occurred in the SSP-saline group.

Conclusion: SWEEPS with the USP mode combined with NaOCl irrigation was effective for elimination of E. faecalis biofilm from the extracted root canals.