Laser activated irrigation with SWEEPS modality reduces concentration of sodium hypochlorite in root canal irrigation.

Introduction: Shockwave enhanced emission photoacoustic streaming (SWEEPS) of Er: YAG laser has been proposed to improve the disinfecting efficacy of endodontic treatments. The purpose of this in vitro study was to compare the effects of different concentrations of sodium hypochlorite (NaOCl) combined with SWEEPS root canal irrigation on the removal of Enterococcus faecalis (E.faecalis) in infected bovine root canals.

Materials And Methods: Forty-eight bovine root canals infected with E.faecalis were randomly divided into six groups. The root canals were irrigated by normal saline (NS) in combination with conventional needle irrigation (CI) , NS and different concentrations of NaOCl (0.5%, 1.0%, 2.0%, and 5.25%) in combination with SWEEPS. Then, the remaining live microbes from all specimens before and after root canal irrigation were collected and recovered via plate counting of the colony-forming unit (CFU). The CFU data were statistically analyzed by the Kruskal-Wallis H test.

Results: After root canal irrigation, the viable count in each group was significantly reduced (P < 0.05). The bacterial reduction in NS+CI and NS+SWEEPS groups was significantly lower than that in other groups (P < 0.05), and there was no significant difference among the other groups, or between these two groups (P > 0.05).

Conclusions: This study showed that SWEEPS used for root canal irrigation can enhance the effect of low-concentration NaOCl while ensuring the antimicrobial effect.