Introduction: This study aims to investigate the efficacy of XP endo finisher and passive ultrasonic irrigation for smear layer removal using scanning electron microscopy (SEM).

Materials and method: The root canals of 36 extracted single rooted mandibular premolars were selected for the study. All specimens were randomly distributed into the following 3 groups: Group I(Control): conventional irrigation by syringe Group II: passive ultrasonic irrigation (PUI) and, Group III: XP endo finisher. In all groups mechanical instrumentation was done with rotary files iRace. The specimens of all the 3 groups was grooved buccolingually along the entire length, with the help of a high- speed bur without perforating into the root canal space. The roots was then split carefully along the length of the groove and subjected to SEM evaluation.

Results: Within the limitation of this study, it can be concluded that XP endo finisher file (XP) was more effective in cleaning the apical area than passive ultrasonic irrigation (PUI) and conventional side vented needle irrigation (CI).