The impact of different flow rate on apically extruded debris and irrigants

Aim: Root canal instrumentation might lead to extrusion of debris and irrigants, leading to postoperative pain and compromised outcomes. Several factors might impact extrusion during root canal instrumentation, including the flow rate in which the irrigant solution is applied inside the root canal. The aim of this study was to assess the extrusion of irrigants and debris with different flow rates of 0.9% saline solution. Matherials and Methods: Thirty mandibular premolars presenting single roots and straight root canals were used in this study. The roots were standardized in 17 mm and inserted in Eppendorf tubes. A 1.5% agar gel was placed inside the tube that involved the roots, while the coronal part of the roots was kept visible. The combination of tube and agar gel was weighted. Then, the specimens were randomly distributed to 3 different groups (n=10) according to the flow rate of the irrigation: Control Group (CG) 5 mL/min, High Flow rate Group (HG) 10 mL/min, and Ultra-High flow rate (UG) 60 mL/min. The canals were instrumented with a Reciproc Blue instrument size 25.08 up to the length of the root, following the manufacturer guidelines. After the instrumentation, the roots were removed and the tube and agar were weighted again. The difference between the final weight and the initial weight represented the total amount extruded beyond the apex. For statistical analysis, the ANOVA test (post-hoc Bonferroni) was used at P>0.05. Results: The mean weight of the extruded debris and irrigants for CG, HG, and UG was respectively 0.0079 ± 0.0087, 0.0110 ± 0.0093, and 0.0083 ± 0.0091. There were no statistically significant differences among the groups. Conclusions: Within the limitations of this study, it can be concluded that the flow rate of irrigants does not impact the extrusion of debris and irrigants.