Computational fluid dynamics analysis of root canal irrigation flow using XP-Endo Finisher, sonic, and ultrasonic activation systems.

PURPOSE: This study aimed to evaluate and compare the flow characteristics and wall shear stress (WSS) generated by the XP-Endo Finisher, sonic, and ultrasonic activation systems using computational fluid dynamics (CFD) analysis. METHODS: A three-dimensional model of a resin-based prepared mandibular premolar was generated from a high-resolution micro-computed tomography (Micro-CT) scan and used for CFD analysis of different irrigation activation systems. Following image segmentation and stereolithography (STL) reconstruction, high-quality tetrahedral meshes with inflation layers were generated and imported into ANSYS Fluent. Irrigant flow during needle irrigation was simulated under steady-state laminar conditions. For the sonic, ultrasonic, and mechanical activation systems, dynamic mesh techniques and user-defined functions were employed to model device-specific oscillatory tip motions based on their respective frequencies and amplitudes. Deterministic CFD outputs, including velocity magnitude and WSS, were compared descriptively among the activation systems. RESULTS: The highest intracanal flow velocity was observed with the EDDY system, followed by ultrasonic activation, EndoActivator, XP-Endo Finisher, and side-vented needle irrigation. A similar trend was observed for maximum WSS, with the EDDY system producing the highest values. Ultrasonic activation ranked second, while EndoActivator, XP-Endo Finisher, and side-vented needle generated progressively lower WSS values. CONCLUSION: All activation techniques demonstrated improved flow dynamics compared to conventional side-vented needle irrigation.