Synergistic effect of manual dynamic agitation and ethylenediaminetetraacetic acid containing 0.25% cetrimide on smear layer removal: An in vitro study

Introduction: This study aims to study the efficiency of manual dynamic agitation (MDA) combined with ethylenediaminetetraacetic acid (EDTA) containing 0.25% cetrimide in smear layer removal of mechanically prepared root canals after final irrigation. Materials and Methods: The root canals of 120 premolars were prepared using Mtwo® rotary instruments. The roots were randomly divided into six groups (n = 20): negative control (G1), irrigated with normal saline, and positive control (G2), irrigated with 17% EDTA followed by 2.5% sodium hypochlorite (NaOCl). The reaming four groups were irrigated with 17% EDTA followed by 2.5% NaOCl with MDA and agitated with gutta-percha (G3), irrigated with 17% EDTA followed by 2.5% NaOCl (both with MDA) (G4), irrigated with 17% EDTA containing 0.25% cetrimide followed by 2.5% NaOCl (both with MDA) (G5), and irrigated with SmearClear™ EDTA followed by 2.5% NaOCl (both with MDA) (G6). Subsequently, the specimens were evaluated under scanning electron microscopy. The amount of smear layer in each specimen, 1 mm, 3 mm, and 5 mm of the apical third of the root canal, was scored using Gutmann's scoring system. Data were statistically analyzed using the Kruskal–Wallis and Mann–Whitney U tests. Results: The least smear layer score was observed in Group 5 (P Conclusions: Supplementation with MDA in the final root canal irrigation step promoted a significantly cleaner surface of the mechanically prepared root canal wall at the apical level. Further, the use of EDTA containing 0.25% cetrimide significantly improved smear layer removal.