Comparative Evaluation of Smear Layer Removal Using Four Different Irrigation Techniques: An in-vitro Study

INTRODUCTION: Irrigation is the vital part of root canal debridement. Usually post biomechanical preparation, the canal walls are covered by smear layer. It is important to remove this layer before obturation for better bond between the filling and walls. Conventional needle irrigation doesn’t give us adequate cleaning, therefore, new irrigation techniques are being tried to facilitate better smear layer removal. AIM: The aim was to evaluate and compare the smear layer removal by PATS,  EndoActivator device, Passive ultrasonic irrigation and side vent needle irrigation from canal walls. MATERIALS AND METHODS:  60 extracted mandibular premolars were instrumented up to 35/.04 with Heroshaper files. Samples were divided into 4 groups randomly before final irrigation as follows: Group I (n=15): Irrigation with side vent needles (Nexus ltd.,India), Group II (n=15): Irrigation with EndoActivator (Advanced Endodontics, Santa Barbara, CA ) Group III (n=15): Irrigation with PATS ( InnovationsEndo,India), Group IV (n=15): Irrigation with ultrasonic tips (Mani inc.). Teeth were split and one-half of each tooth was chosen for SEM examination.  The images were taken at apical third and scoring was done according to criteria by Torabinejad et al in 2003. Data obtained were analyzed using Kruskal-Wallis analysis of variance followed by Mann–Whitney U-test for individual comparison. RESULTS: All irrigating systems remove smear layer but PUI has better cleaning ability as compared to other groups. CONCLUSION: Passive ultrasonic irrigation shows better smear layer removal as compared to other technique