The Effect of Using Different Kinematics Single File Systems with Coronal Preflaring Instruments on Postoperative Pain with Symptomatic Irreversible Pulpitis: A Randomized Clinical Trial

The aim of this study was to investigate the effect of using coronal preflaring file (One Flare; OF) with rotational (One Curve; OC) and reciprocal (WaveOne Gold; WOG) single file systems on postoperative pain in mandibular premolar teeth with symptomatic irreversible pulpitis. Eighty patients were included in this prospective, superiority, parallel, and randomized controlled clinical trial. The patients were randomly divided into four groups (n = 20) based on the use of coronal preflaring and the kinematics of the shaping instrument: WOG (without coronal preflaring), WOG with coronal preflaring (OF), OC (without coronal preflaring), and OC with coronal preflaring (OF). Patients recorded their postoperative pain intensity at 6, 24, 48, and 72 hours using a 10-cm visual analog scale. Friedman and Wilcoxon's tests were used for intragroup comparisons, and Kruskal–Wallis test was used for intergroup comparisons. The post hoc analysis was performed using Dunn's test. The Chi-square test was used to compare gender and tooth localization according to the groups, and Kruskal-Wallis test was used to compare age and preoperative pain (P