Effect of Heat and Irrigation Agitation on the Smear Layer Removal Ability of Calcium Hypochlorite: A Scanning Electron Microscope Study

This study aims to evaluate the efficacy of calcium hypochlorite in smear layer removal during root canal treatment and examine the impact of heat and agitation techniques on its performance. In this study, 160 single-rooted, straight mandibular premolars were prepared using ProTaper Next rotary files up to X4. Following preparation, samples were randomly branched into 10 groups of 16 teeth each. 5.25% calcium hypochlorite was used at 3 different temperatures: non-heated, preheated, and intracanal heated. As agitation techniques, XP-Endo Finisher, EDDY, and Passive Ultrasonic Irrigation (PUI) were used. The teeth were divided into two longitudinal sections and examined under a scanning electron microscope at ×1000 magnification. The control group exhibited the highest smear layer retention in all regions, while the intracanal heated PUI group provided the most effective cleaning in all areas. The results showed that heating calcium hypochlorite and using agitation techniques are more effective for smear layer removal.