The efficacy of laser, ultrasound and self-adjustable file inremoving smear layer debris from oval root canals followingretreatment: A scanning electron microscopy study

The purpose of this study, the effectiveness of different irrigation activation methods, used in the removal of debris and smear layer in the oval-shaped channel, compared with conventional irrigation methods. So, the methods are more effective for root canal have been identified. 90 oval-shaped lower canine teeth root canals were prepared and filled with warm vertical compaction technique. Retreatment was performed with rotary files. Samples were divied randomly into 6 groups (n = 15) and different agitation techniques were applied each group with the same irrigation protocols: R-Endo retreatment files, R-Endo + Er: YAG laser, R-Endo + PIPS laser, R-Endo + Nd: YAG laser, R- Endo + SAF, R-Endo + Ultrasonic. Then all root canals were divided longitudinally to evaluate with SEM. The number of open dentinal tubules and surface area covered with debris were assessed using SEM images. Between-group comparisons of variables Kruskal Wallis test and differences in the determination of the cause must be modified Bonferroni Mann-Whitney U test was used. The parameters of intragroup comparisons should be modified Bonferroni at the Friedman test and Wilcoxon signed rank test was used for pairwise comparisons. Wilcoxon Sign Test was used for intergroup comparison of two points. Significance of p <0.05 was considered. It was determined that the smear layer from the coronal to the apical region progressed towards reduced. Particularly in the coronal region: the smear layer obtained Er: YAG laser group were significantly lower than the other groups (p <0.05). In our study was observed to be more successful than traditional methods of each group.