comparison of the root canal cleaning efficacy of three irrigation methods, XP-endo Finisher, EDDY, and PUI at different apical  sizes: an in vitro study

Abstract Objectives To compare the effects of three irrigation methods (Passive Ultrasonic Irrigation (PUI), EDDY, and XP-endo Finisher (XPF)) in removing the smear layer of the curving root canals under different apical sizes.Material and methods Seventy-two mesial roots of mandibular molars were divided into nine groups according to different apical sizes and the irrigation protocols: group A1 (size 25, EDDY), group A2 (size 25, XPF), and group A3 (size 25, PUI); group B1 (size 30, EDDY),group B2 (size 30, XPF), and group B3 (size 30, PUI); group C1(size 35, EDDY),group C2 (size 35, XPF), and group C3 (size 35,PUI).The irrigation effect was evaluated by scanning electron microscopy at ×3000 magnification using a 5-point scoring system and statistically analyzed by Kruskal-Wallis and Mann-Whitney tests. Results The application of PUI in mandibular molars should be prepared with the apical size of at least size 35(P＜0.05), and that of EDDY and XPF should only be prepared to size 25(P＜0.05).Conclusion Irrespective of the irrigation activation methods,none could completely remove the smear layer,while EDDY and XPF have a better cleaning effect than PUI under smaller apical size.Clinical relevance EDDY and XPF can be used as safer and more efficient irrigation activation devices.