Insights of fluid dynamics in an optimally shaped root canal system

Abstract

Dear Editor, Fluid flow patterns are investigated and understood only at in vitro levels through laboratory-based studies.[1] Various physical parameters play a crucial role in enhancing the irrigant flow in a prepared canal space. Ideally, the physiological limit of the irrigant must be restricted within the canal space and also it might not be clinically possible to specifically determine the exact value when the irrigant exceeds the optimal flow rate. Laboratory-based studies proved 1–4 ml/min to be the optimal flow rate to prevent inherent extrusions and apical pressures.[2,3] Although the in vitro literature focused more on syringe needle irrigation,[1] in routine clinical practice with the use of manual needle irrigation, it might not be possible to obtain maximum disinfection. The current clinical literature is now more focused on the efficacy of activation systems with less preference to manual irrigation techniques.[4,5] Previous study showed 30G side vented needles to be the most frequently used[6] and induce the least pressure at a specified irrigant flow rate.[1] However still, the existing literature evidence has not given insights into the fluid dynamics of various activation systems and also the complex nature of the irrigant flow pattern is unexplored. As the irrigant flow rate cannot be standardized on activation, there is an urge for future research which specifically investigates the irrigation dynamics of using various activation devices. Hence, the tendency of irrigant extrusions with various activation devices and the complexity of fluid dynamics are yet to be investigated, especially considering the various physical parameters, including the velocity, turbulence, and shear wall stress considering the induced apical pressures. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.