Development and validation of a three-dimensional computational fluid dynamics model of root canal irrigation.

Root canal irrigation plays an important role in the debridement and disinfection of the root canal system and is an integral part of root canal preparation procedures. The aim was to construct a three-dimensional computational fluid dynamics (CFD) model of root canal irrigation, with a suitable turbulence model, and validate it to provide a novel method for studying the root canal irrigation. A camcorder was used to record the effect of irrigation in the in vitro model. An exact replica of the geometry and the physical parameters of the in vitro irrigation model were used in CFD analysis, considering four turbulent models. The in vitro irrigation model was used as the reference for the evaluation of the CFD models. The result showed that CFD analysis based on a shear stress transport (SST) k-omega turbulence model was in close agreement with the in vitro irrigation model. The in vitro and CFD analyses showed that the irrigant in the curved canal flushes only up to a limited distance beyond the tip of the needle. The results of the CFD analysis also showed that laminar flow exists in the needle lumen and transit the transitional and turbulent flow around the side-vent outlet of the needle and needle tip. The results suggested that CFD based on a SST k-omega turbulence model has the potential to serve as a platform for the study of root canal irrigation.