Insights of fluid dynamics in an optimally shaped root canal system : Saudi Endodontic Journal

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Letter to Editor

Insights of fluid dynamics in an optimally shaped root canal system

Teja, Kavalipurapu Venkata; Ramesh, Sindhu; Janani, Krishnamachari1

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Saudi Endodontic Journal 13(2):p 216, May–Aug 2023. | DOI: 10.4103/sej.sej_216_22
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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.

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1. Teja KV, Ramesh S, Battineni G, Vasundhara KA, Jose J, Janani K. The effect of various in-vitro and ex-vivo parameters on irrigant flow and apical pressure using manual syringe needle irrigation:Systematic review. Saudi Dent J 2022;34:87–99.
2. Khan S, Niu LN, Eid AA, Looney SW, Didato A, Roberts S, et al. Periapical pressures developed by nonbinding irrigation needles at various irrigation delivery rates. J Endod 2013;39:529–33.
3. Choudhari S, Teja KV, Ramesh S, Jose J, Janani K, Kumar R. Assessment of apical pressures at different automated irrigant flow rates:An ex vivo study based on computational fluid dynamic analysis. Braz Dent Sci 2022;25:1–6.
4. Susila A, Minu J. Activated irrigation versus conventional non-activated irrigation in endodontics –A systematic review. Eur Endod J 2019;4:96–110.
5. Cheung AW, Lee AH, Cheung GS. Clinical efficacy of activated irrigation in endodontics:A focused review. Restor Dent Endod 2021;46:e10.
6. Teja KV, Ramesh S, Choudhari S, Janani K, Jose J, Vasundhara KA. A questionnaire-based cross-sectional survey of Indian postgraduates and endodontists on awareness, attitude, and practice of using conventional syringe needle irrigation during root canal treatment. Saudi Endod J 2022;12:302.
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