Efficacy of calcium hypoclorite with and without Er,Cr: Yttrium, scandium, gallium, garnet laser activation on Enterococcus faecalis in experimentally infected root canals.

Abstract

The aim of this study was to compare the antimicrobial efficacy of calcium hypochlorite (Ca(OCl)2) and sodium hypochlorite (NaOCl) associated with or without erbium, chromium: yttrium, scandium, gallium, garnet (Er,Cr: YSGG) laser irradiation in root canals experimentally infected with Enterococcus faecalis. The root canals of 105 single-rooted premolars were enlarged up to file 40, autoclaved, inoculated with E. faecalis, and incubated for 21 days. The teeth were randomly divided into seven experimental (n = 15) groups according to the protocol for decontamination: syringe irrigation (SI) with distilled water (DW), SI with 2.5% NaOCl, SI with 2.5% Ca (OCl)2, laser-activated irrigation (LAI) with DW, LAI with 2.5% NaOCl and LAI with 2.5% Ca (OCl)2 and LAI with no solution. Microbiological samples were collected and the colony-forming units were counted before and after irrigation procedures and the percentages of reduction were calculated. Mean numbers of recovered bacteria in the SI with DW group were significantly higher than those in the other experimental groups (P < 0.05). The high bactericidal reduction was observed in any of the other treatment groups: SI using NaOCl or Ca (OCl)2 and LAI with DW, NaOCl, Ca (OCl)2 or no solution, with no statistically significant difference. Er,Cr: YSGG laser with or without an irrirgation solution has antimicrobial effects on dentinal tubules infected with E. faecalis. The antimicrobial property of 2.5% Ca (OCl)2 was effective as 2.5% NaOCl on E. faecalis with conventional or laser activated irrigation in root canals.