Comparative Evaluation of Postoperative Pain After Root Canal Preparation with Rotary (Hyflex EDM) vs Reciprocating (Reciproc VDW) System in Molar Teeth: A Randomized Controlled Trial

Objective: To evaluate and compare postoperative pain experienced by patients undergoing root canal treatment using continuous rotation (Hyflex EDM) vs reciprocating (Reciproc) instrumentation systems. Study Design: Randomized controlled trial (NCT06779565). Place and Duration of Study: 21 Military Dental Centre, Quetta, Pakistan, from Aug 2024 to Jan 2025. Methodology: Patients were randomly divided into two groups to receive root canal therapy using either the Reciproc or Hyflex EDM instrument systems. The therapy was carried out over two sessions, and postoperative pain was measured using the Numerical Rating Scale (NRS) at intervals of 6-, 12-, 18-, 24-, 48-, and 72-hours after treatment. Post-operative swelling was recorded using a modified Gabka and Matsumura Scale. Results: Group-A (Hyflex EDM) and Group-B (Reciproc) had the same distribution of gender, pulp vitality, and tooth type. The mean numerical rating scale score was significantly higher in Group-B compared to Group-A at all-time points (p < 0.05). Except for 48 hours during the first visit, Group B's mean swelling was significantly higher than Group-A's at 6-, 12-, 18-, and 24-hour periods. On the contrary, a significant difference was observed at the second visit after 6 hours (p = 0.041). Conclusion: The Hyflex EDM system significantly reduces postoperative pain after endodontic therapy compared to the Reciproc system