To compare the continuous and intermittent irrigation method on the removal of dentin debris from root canals and to evaluate the dynamics of irrigant flow using computational fluid dynamics

Abstract

Aim: This study aimed to compare the efficiency of continuous and intermittent irrigating methods on the removal of dentin debris from the simulated grooves and to evaluate the dynamics of irrigant using computational fluid dynamics (CFD). Methodology: Seventy-five extracted human permanent maxillary canines were selected. Access cavities were made, working length was determined, and canals were prepared by crown down technique. The teeth were split longitudinally and standard groove 2.0 mm in length was made in split halves and each groove was filled with dentin debris and the images were taken under a microscope (E200). The halves were re-assembled and divided into five groups based on different irrigation methods. Group 1: ultrasonic Irrigation with continuous flow for 3.0 min; Group 2: ultrasonic irrigation with continuous flow for 1.5 min; Group 3: ultrasonic irrigation with intermittent flow for 3.0 min; Group 4: ultrasonic irrigation with the intermittent flow for 1.5 min; and Group 5: syringe irrigation for 1 min. The root halves were again separated and re-evaluated for debris elimination after the irrigation protocol for all the groups separately. The effect of time and method of passive ultrasonic irrigation were compared. For the computational fluid analysis, a GAMBIT 2.2 (Ansys) software was used for mesh construction. FLUENT 6.2 (Ansys) software was used to set the boundary conditions and reconstruction of the canal; flow patterns and turbulence were graphically constructed. Results: The continuous irrigation methods were better at debris removal than intermittent irrigation flow methods. The CFD showed that the turbulence of flow of irrigant was dependent on the inlet velocity and pressure of the irrigant. Conclusion: Debris removal from the simulated grooves was better with continuous irrigation compared with intermittent irrigation. CFD study revealed that the turbulence that was affected by the velocity and pressure of the irrigant introduced and is a variable entity.

Computational fluid dynamics in root canal irrigation

“…In addition, ultrasonic irrigation can be used in two different methods, one was continuous irrigation with irrigant delivering into the root canal continuously, and the other was intermittent irrigation with the discontinuous flow but the same cumulative irrigation time. Raj et al 46 reported that continuous irrigation had a better effect on the removal of debris in simulated grooves than intermittent irrigation. It was because continuous irrigation helped in the continuous activation of the irrigant and thus led to better debridement of the root canal.…”

Farklı İğne Tasarımlarının Diş Kanalı İrrigasyonu Üzerindeki Etkilerinin Hesaplamalı Akışkanlar Dinamiği ile İncelenmesi

“…Therefore, irrigation is essential to remove debris and to obtain disinfected root canal system, although there are new methods for root canal irrigation, such as sonic or ultrasonic activation, the conventional root canal irrigation method still has common use among dentists for root canal treatment [9]. Effectiveness and the safety of the root canal irrigation depends on several factors and various methods have been proposed to test these parameters in the last decade ( [10], [11], [12], [13], [14] and [15]), however these methods provided insufficient insight into the irrigation process [16]. Computational Fluid Dynamics (CFD) is finite-volume based numerical solution technique for fluid dynamics problems [17].…”

“…Computational Fluid Dynamics (CFD) is finite-volume based numerical solution technique for fluid dynamics problems [17]. CFD is a powerful method to evaluate flow characteristics by means of streamlines, velocity distributions, shear stresses and pressure on the root canal wall, that are difficult to measure in vivo due to the complex anatomy of the root canal [16]. CFD can be considered as a promising tool to investigate the effect of needle tip design on root canal irrigation and potential irrigant extrusion risks, as in many engineering problems.…”