Photobiomodulation for postoperative pain relief following conventional periapical surgery: a randomised controlled study protocol.

INTRODUCTION: Photobiomodulation (PBM) has shown promising effects in managing postoperative pain following conventional periapical surgery, although current evidence remains limited. This study aims to assess the effect of PBM on postoperative pain 24 hours after periapical surgery. METHODS AND ANALYSIS: A randomised, controlled, double-blind trial will include 34 patients undergoing periapical surgery in the maxillary region, randomly assigned to an experimental group (n=17) or control group (n=17). The experimental group will receive PBM (GaAlAs diode laser, 808 nm, 100 mW, 4 J/cm², applied at five vestibular points) and placebo ibuprofen immediately and 24 hours postoperatively. The control group will receive simulated PBM and active ibuprofen. The primary outcome is postoperative pain assessed by the visual analogue scale at 24 hours. Secondary outcomes include pain at the seventh day, paracetamol intake, oedema, ecchymosis, soft tissue status and temperature at 24 hours and 7 days. Radiographic evaluation of healing will be performed at 1 and 3 months. Statistical analysis will be conducted based on data distribution, using repeated measures ANOVA (Analysis of Variance) or non-parametric equivalents for longitudinal outcomes, and appropriate tests for categorical variables. Significance will be set at p<0.05. ETHICS AND DISSEMINATION: The study was approved by the Human Research Ethics Committee of Universidad Católica del Uruguay (process no. 220914). Results will be disseminated to participants, healthcare professionals, the public and scientific communities. TRIAL REGISTRATION NUMBER: NCT05935306.