Evaluation of Single-Visit Post-endodontic Discomfort Using Three Different Rotary File Systems: An In Vivo Study

Introduction Postoperative pain following single-visit root canal treatment (RCT) remains a common clinical concern and is likely influenced by multiple factors, including instrumentation technique, apical debris extrusion, and mechanical stress on the periapical tissues. The aim of the present study was to evaluate and compare postoperative discomfort following single-visit RCT using three different rotary file systems. Materials and methods This prospective clinical observational study included 135 patients diagnosed with asymptomatic irreversible pulpitis of the posterior mandibular teeth. The participants were treated using one of three rotary systems: TruNatomy, GenEndo, and Jizai (n = 45 per group). All procedures were performed under standardized clinical conditions using a single operator. Postoperative pain was assessed using a visual analog scale (VAS) at 24 h, 48 h, 72 h, and 7 days. Statistical analyses were performed using IBM SPSS Statistics for Windows, Version 26 (Released 2018; IBM Corp., Armonk, NY, USA). Data were analyzed using the Friedman test for intragroup comparisons and the Kruskal-Wallis test with Mann-Whitney U post-hoc analysis for intergroup comparisons. Statistical significance was set at p < 0.05. Results All groups demonstrated a statistically significant reduction in VAS scores over time (p < 0.001). The TruNatomy group showed the lowest mean pain scores, decreasing from 1.84 ± 0.90 on Day 1 to 0.69 ± 0.76 on Day 7. In comparison, GenEndo showed a reduction from 4.07 ± 1.25 to 2.38 ± 0.89, and Jizai from 4.02 ± 1.27 to 2.60 ± 0.78. Intergroup analysis revealed significantly lower pain scores in the TruNatomy group than in the GenEndo and Jizai groups at all time points (p = 0.001), while no significant difference was observed between the GenEndo and Jizai groups (p > 0.05). Conclusion All rotary systems reduced postoperative pain over time. However, the TruNatomy group was associated with significantly lower postoperative pain scores compared to GenEndo and Jizai under the conditions of the present study. Its flexible and minimally invasive design may contribute to reduced periapical irritation and improved patient comfort. The selection of appropriate instrumentation systems can play an important role in minimizing postoperative discomfort in single-visit endodontic therapy.