Protocol for low-level laser therapy (LLLT) to control post-endodontic treatment pain in patients with apical periodontitis: a randomized controlled trial.

Background: Pain after endodontic therapy affects from 2.5 to 60% of patients and may significantly impacts patient's quality of life and adherence to dental treatment. This blind clinical trial protocol was designed to evaluate the analgesic effect of low-level laser therapy (LLLT) and its impact on post-operative pain and on quality of life (QoL) in patients with apical periodontitis (AP) submitted to root canal treatment (RCT).

Methods: 116 patients will be selected. RCT will be performed using the ProTaper Next system. Patients will be randomly allocated into 2 groups: control (naproxen prescription) and test (LLLT). Post-operative pain levels will be assessed through numeric raking scale (NRS) before intervention and at 6 h, 12 h, 24 h and 72 h after endodontic procedures. Quality of life will be assessed using the OHIP-14 before intervention, post-preparation, post-obturation and 6 months after RCT. Descriptive statistics and normality tests will be carried out, and comparison between groups will be estimated for each outcome (post-operative pain and QoL) using parametric or non-parametric tests. The significance level will be set to 5%.

Discussion: This study has the potential to strengthen the evidence on postoperative pain management in Endodontics by exploring efficient and safer protocols. Additionally, it may improve the QoL of patients affected by AP.

Trial registration: Clinicaltrials.gov registration: RBR-5hgcgy4, registered on 31/07/2023, https://ensaiosclinicos.gov.br/rg/RBR-5hgcgy4 . Ethics Reference No: 22706919.0.0000.5336. Trial Sponsor: Pontifical Catholic University of Rio Grande do Sul. The Trial was prospectively registered.