{Reference Type}: Journal Article {Title}: The efficacy of laser, ultrasound and self-adjustable file in removing smear layer debris from oval root canals following retreatment: A scanning electron microscopy study. {Author}: Keles A;Kamalak A;Keskin C;Akçay M;Uzun İ; {Journal}: Aust Endod J {Volume}: 42 {Issue}: 3 {Year}: Dec 2016 {Factor}: 1.719 {DOI}: 10.1111/aej.12145 {Abstract}: This study aims to compare the efficacy of different irrigation activation methods to remove smear layer and debris from oval-shaped root canals following retreatment. Ninety mandibular canines with oval-shaped root canals were selected. Retreatment was performed with R-Endo retreatment files. The samples were randomly divided into six groups (n = 15). Groups were assigned according to agitation technique: R-Endo with classic irrigation, with self-adjustable file, with passive ultrasonic irrigation, R-Endo + Er:YAG, R-Endo + PIPS and R-Endo + Nd:YAG. Compared with the classic irrigation (R-Endo + CI) group, all other groups were more successful in reducing smear layer and debris (P < 0.05). The least amount of residual smear layer and debris was detected in the Er:YAG laser group (P < 0.05). Additional use of different agitation methods contributes to removal of debris and smear layer following root canal filling removal with rotary instruments; however, none of the techniques tested render root canal walls completely free of smear layer or debris.