Effectiveness of photobiomodulation in reducing pain and producing dental analgesia: a systematic review.

PURPOSE: Photobiomodulation (PBM) is reported in many studies to produce dental analgesia without producing thermal damage to tissues. This systematic review aims to assess in vivo studies to support the statement that PBM can produce dental analgesia. METHOD: A systematic search strategy was constructed, and PubMed, Scopus, and Embase databases were searched. Subsequently, inclusion and exclusion criteria were applied, reference lists were scanned, and hand searched to identify other suitable studies. RESULTS: Five studies met the inclusion criteria. Meta-analysis was not undertaken due to the heterogenous nature of the studies and data. Positive analgesia outcome was obtained in four out of five studies, and one study with no significant results was criticized for poor reporting of laser parameters, small sample size (six). CONCLUSION: In general, all studies were criticized for poor discussion of all covariates that could have modified the results, consequently resulting in poor quality of evidence, moderate risk of bias, and poor internal validity, as well as external validity. The systematic review also discussed the potential implications of all variables to be considered for future trials, including pulsing mode, contact modes, and tooth characteristics.