Effectiveness of different irrigation devices on the smear layer removal in the apical portion of curved root canals: A scanning electron microscopy study

Aim: The aim of this study is to evaluate the smear layer removal efficiency of Max-I-Probe, EndoActivator, and EndoVac at three different levels in the apical portion of curved root canals. Materials and Methods: Mandibular molars with angles of root curvature between 25 and 40 degrees were selected and divided into three groups. The specimens were instrumented to size 35/0.04. Group 1 received conventional irrigation with Max-I-Probe needle; Group 2 and Group 3 were irrigated with EndoActivator and EndoVac, respectively. Following shaping and cleaning, the roots were observed under scanning electron microscope for smear layer at three levels (1 mm, 3 mm, and 5 mm from working length). One-way analysis of variance was calculated and to find the exact significance among the groups a post hoc test, i.e., Bonferroni test was performed. Results: The level of significance was set as P < 0.05. The EndoVac system resulted in a significantly better smear layer removal than the Max-I-Probe needle at all levels. The EndoVac also demonstrated enhanced smear layer removal than the EndoActivator at 3 mm and 1 mm levels. Conclusions: The application of EndoVac system could enhance smear layer removal at the apical portion of curved canals