(PO79) A Computational Fluid Dynamics Analysis Comparing Irrigation within Complex Anatomy of Canals Shaped with Minimally Invasive and Progressively Tapered Instruments using Different Irrigation Methods

Abstract:
The aim of this study was to compare the fluid dynamics in complex root canal systems shaped with minimally invasive versus progressively tapered file systems using single and double side-vented 30-gauge irrigation tips at four different flow rates. Two identical plastic mandibular molars were instrumented using minimally invasive and progressively tapered files and scanned via micro-computed tomography. A computational fluid dynamics model was created and enhanced with apical ramifications in the distal root and an isthmus in the mesial root. The model was utilized to replicate irrigation within complex canal anatomy using both a single and double side-vented 30-gauge irrigation tip at four flow rates: 0.05, 0.10, 0.15, and 0.20 mL/s. For all groups, as the inlet flow rate increased, the canal flow rates, average wall pressure, and wall shear stress increased. The average wall pressure and wall shear for the distal root were highest in the minimally instrumented canals using a single side-vented irrigation tip and lowest when the canals were progressively instrumented using a double side-vented irrigation tip. The average shear stress in the mesial root was highest in the isthmus and secondary canals when minimally invasive instrumentation and a single side-vented irrigation tip were used and lowest when the canals were progressively instrumented using a double side-vented needle. Teeth with complex anatomy are irrigated most efficiently when instrumented minimally invasively, using a high flow rate and with a single side-vented, 30-gauge irrigation tip..