Effect of low-level laser therapy versus calcium hydroxide intra-canal medication on postoperative pain and inflammatory mediator reduction in symptomatic apical periodontitis: a randomized clinical trial

Abstract

Abstract Background Post-operative pain following root canal therapy remains a prevalent clinical issue, especially in cases of symptomatic apical periodontitis, where inflammatory mediators such as interleukin-8 (IL-8) and substance P are critically involved in the pathophysiology. This study aimed to assess and compare the efficacy of LLLT and Calcium Hydroxide (CH) as intracanal medication in alleviating post-operative pain, percussion sensitivity, and in reducing the levels of IL-8 and substance P in periapical exudate one week after root canal instrumentation in patients with symptomatic apical periodontitis. Methodology This comparative, parallel-design randomized clinical trial evaluated the effectiveness of low-level laser therapy (LLLT) versus Calcium Hydroxide in managing post-operative pain in 48 patients with symptomatic apical periodontitis. Patients aged 20–55 with mature, single-canalled permanent teeth were randomly assigned (1:1) to either treatment group using computer-generated randomization with concealed allocation. Root canal therapy was performed over two visits, with pre- and post-operative pain and percussion sensitivity recorded at different time intervals. Periapical fluid samples were collected immediately post-instrumentation (PS-1) and after one week (PS-2) to quantify substance P and IL-8 using ELISA. Blinding was maintained for the molecular biologist and the statistician. Data were analyzed using SPSS v25.0. Results Two patients were lost to follow-up; therefore, 46 patients were included in the analysis. Statistical analysis revealed no significant differences between the LLLT and Calcium Hydroxide groups in terms of postoperative pain at any assessed time point, nor in percussion pain at 1-week post-instrumentation (p > 0.05). Furthermore, the reduction in substance P and IL-8 concentrations between PS-1 and PS-2 samples did not differ significantly between groups (p = 0.123 and p = 0.385, respectively). Conclusion Within the Limitations of this study, it may be concluded that LLLT may be considered a viable single-visit treatment option and an effective alternative to Calcium Hydroxide for the management of Symptomatic Apical Periodontitis, as both demonstrated comparable clinical pain relief and biochemical modulation of IL-8 and Substance P. Trial registration number NCT04594317 on Clinicaltrials.gov on 13th of oct. 2020.