Low-level Laser Therapy and Changes in Salivary Proinflammatory Cytokines: A Systematic Review

Background: The effect of laser on reducing inflammation has always been considered. The aim of this study was to evaluate the clinical studies on the effect of using low-power lasers on the production and activity of proinflammatory cytokines such as IL-1, IL-6, and TNF-α.Methods: This study is a systematic review of Google Scholar, PubMed, and SCOPUS database articles which was conducted from 1990 to 2021. All information was categorized in a table.Results: In the review conducted in the mentioned databases and according to the considered time period, 239 articles related to the searched terms were found through the abstract. After removing duplicate titles and articles, 31 articles were selected and a more detailed review by the evaluation team yielded 16 articles. The full texts of these 16 articles were reviewed. For the final selection, 13 articles met the inclusion criteria and included the objectives of the present study.Conclusion: Understanding the true mechanisms of low-level laser therapy (possible photochemical, photomechanical, and photobiological changes) and examining the relationship between cellular effects and changes in cytokines and clinical phenomena require numerous controlled clinical trials to develop an effective treatment protocol.