Abstract
BACKGROUND: Postoperative pain is a common complication following endodontic treatment, often caused by acute inflammatory responses in the periapical tissues. Several factors contribute to this, including inadequate instrumentation, apical extrusion of debris during canal preparation, and other aspects of the procedure. Advances in technology have led to the development of nickel-titanium (NiTi) instruments that have shown potential to reduce postoperative discomfort. The purpose of this study was to evaluate postoperative pain in patients undergoing endodontic treatment with different NiTi systems. METHODS: This randomized clinical trial will include 128 patients between the ages of 18 and 50 years with a diagnosis of pulp changes in molars without pain or radiographic lesions requiring endodontic treatment. Patients will be randomized to receive root canal preparation with the rotary ProTaper Ultimate rotary system or the Reciproc Blue reciprocating single-file system. The primary outcome will be the intensity of postoperative pain measured by a numerical rating scale (NRS-10 cm) in 24 h postoperatively. Secondary outcomes will include the intensity of postoperative pain measured by a visual analog scale (VAS-0-10 cm) at 6 and 12 h and spontaneous pain, occlusion sensitivity, and quality of life, assessed by the OHIP-14 questionnaire. DISCUSSION: Our null hypothesis is that there will be no significant difference in postoperative pain between the two systems. The results of this study will provide information on the incidence and intensity of postoperative pain after instrumentation of root canal instrumentation with different NiTi systems and may help improve patient outcomes and quality of life. TRIAL REGISTRATION: Brazilian Clinical Trials Registry (REBEC): RBR-10kbw6nx. Registered on April 6, 2024.