Effectiveness of Photobiomodulation on Orthodontic Mini Screw Stability: A Systematic Review

Objective: Photobiomodulation therapy (PBMT) enhances bone regeneration and bone healing and has been suggested to improve the stability of orthodontic mini screws. This study aimed to systematically review the clinical influence of PBMT on orthodontic mini screw stability.Methods: A comprehensive search was run in the following electronic databases: PubMed, EMBASE, Web of Science, Scopus, and Cochrane. The clinical trials reporting the effects of PBMT on mini screw stability in human subjects were included. Two reviewers independently screened and extracted data. The Cochrane Risk of Bias Assessment Tool was used to investigate the quality of the included studies. The overall quality of evidence was evaluated through the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach. The primary outcome was the stability of mini screws, and the secondary outcomes were pain, inflammation (the interleukin [IL]-1ss, IL6, and IL8), and overall success rate. Quantitative synthesis could not be performed due to heterogeneities among studies.Results: Seven articles were finally included in the present review. Moderate-quality evidence suggests that if the PBMT continues until the third or fourth week, the stability of min screws would be promoted from the third to the eighth week after insertion. Although the evidence for secondary outcomes was limited, PBMT could positively affect the inflammation.Conclusions: PBMT exerted varying effects on the stability of mini screws at different time intervals. However, despite the limitations of studies, it seems to enhance the secondary stability of orthodontic mini screws primarily.Registration: The study protocol was registered on PROSPERO (https://www.crd.york.ac.uk/PROSPERO/) with the ID#CRD42020194058.