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Comparison of cleaning efficacy of various irrigation methods

Purpose: The aim of this study was to evaluate the cleaning efficacy of two irrigation activation systems. Materials and Methods: Sixty single-rooted human teeth were mechanically prepared and randomly divided into three groups: group 1 (control)-manual needle irrigation; group 2 (EA, EndoActivator; Dentsply, Tulsa, OK, USA)-irrigation activation with sonic device; group 3 (CK, CK file; B&L Biotech, Ansan, Korea)-irrigation activation with ultrasonic device. After irrigation, longitudinal grooves were made with a diamond disk on buccal and lingual surfaces of all teeth, after which horizontal grooves were made on 3 mm from the apex of all roots. Then, all teeth were split by a chisel to obtain 3 mm-sized cross-sectioned samples of the apex area, and the remnants were discarded. Each cross-sectioned sample was dehydrated and evaluated by scanning electron microscope. Data were analyzed by means of the Kruskal-Wallis test and Mann-Whitney U test (p<0.05). Results: Groups treated with EndoActivator (group 2) and CK file (group 3) showed significantly higher removal of the smear layer than the group treated with manual needle irrigation (group 1) (Kruskal-Wallis test, p<0.05). However, there was no significant difference between group 2 and group 3 (Mann-Whitney U test, p<0.05). Conclusion: Both irrigation activation systems, EndoActivator and CK file, were more effective in removing smear layer from the apical 3 mm region of the root canal than the manual needle irrigation method.