In vitro analysis of two irrigation activation systems for cleaning mesial canals in lower molars

Abstract

Introduction: this study aimed to compare the efficacy of two different endodontic activation systems in removing debris from the mesial canals of mandibular molars across root thirds. Methods: the mesial canals of fifteen human mandibular first molars were prepared with files, irrigated with 2.5 % sodium hypochlorite and 17 % EDTA, and divided into three groups (n=5) based on the type of activation: Control (activation with master cone), Ultrasound Irrigation (UI), and Ultra X (Passive Ultrasonic Irrigation - PUI). The roots were sectioned into thirds (cervical, mid, and apical), exposing root canals, and prepared for scanning electron microscopy. A total of 135 microphotographs (3 microphotographs for each root level) were obtained. To determine the most effective activation system, three calibrated endodontic specialists evaluated all images. Data were analyzed using the Kruskal-Wallis test (95 %). Results: the PUI system demonstrated the highest efficacy, followed by UI, while the control was the least efficient (p<0.001). Significant differences were found between PUI and the other systems at each root level: Control (p=0.039), UI (p=0.327), and PUI (p=0.024). Root canal cleaning decreased from cervical to apical in all groups, with the UI group showing a more regular cleaning pattern at all levels. Conclusion: the PUI system was the most effective, followed by UI. The efficacy of the activation systems decreased as the working depth increased.

Keywords

• edetic acid
• ultrasonics
• root canal preparation
• endodontic
• smear layer
• capa de barro dentinario
• ácido edético
• ultrasonido
• preparación del conducto radicular
• endodoncia