Evaluation of Er,Cr:YSGG laser activation, manual dynamic and conventional irrigation for smear layer removal using different sodium hypochlorite irrigating solutions

Background The purpose of the present study was to microscopically evaluate the influence of Er,Cr:YSGG laser, manual dynamic, and conventional methods on smear layer removal of different NaOCl solutions at the apical, middle, and coronal regions of root canal walls. Methods One hundred & eight freshly extracted human single-canal anterior teeth were enrolled in this study. The teeth were decapitated & their canals were instrumented to size X4, 0.06 taper using rotary files of ProTaper Next® system. According to type of agitation technique, the teeth were classified into three groups (36 teeth each); no activation (traditional), manual dynamic, & Er,Cr:YSGG laser-activated techniques. Each group were further subdivided into four subgroups based on the irrigant type & concentration (n = 9); saline and 1%, 2.5%, and 5.25% NaOCl. Samples were gently split, longitudinally for SEM evaluation. Kruskal-Wallis and Mann-Whitney tests were used for statistical analysis. Results Regardless the irrigant type & concentration, Er,Cr:YSGG Laser-activated & manual dynamic groups showed better smear layer removal values than that of conventional group. Conclusion Er,Cr:YSGG laser-activated irrigation can eliminates more smear layer compared manual dynamic, & conventional techniques which increasing the cleaning capacity of different root canal irrigants.