Influence of low-level-laser therapy on the stability of orthodontic mini-screw implants. A systematic review and meta-analysis.

ABSTRACT

BACKGROUND: The influence of low-level-laser therapy (LLLT) on the stability of orthodontic mini-screw implants (MSIs) has not been systematically reviewed. OBJECTIVES: The aim was to assess the influence of LLLT on the stability of orthodontic MSIs. METHODS: An unrestricted search of indexed databases was performed. SELECTION CRITERIA Randomized controlled clinical trials (RCTs) investigating the influence of LLLT on orthodontic MSI stability. DATA COLLECTION AND ANALYSIS: Two authors independently performed study retrieval and selection, and data extraction. The risk of bias (RoB) of individual studies was assessed using the Cochrane RoB Tool for RCTs. Meta-analyses were performed separately for RCTs using periotest and resonance frequency analysis (RFA) to measure MSI stability; and a random effects model was applied. Subgroup analyses were performed based on the time-points of MSI stability evaluation. The quality of available evidence was evaluated using the Grades of Recommendation, Assessment, Development, and Evaluation approach. RESULTS: Initially, 1332 articles were screened. Six RCTs with a split-mouth design were included. The periotest was used in 4 RCTs and 2 RCTs used RFA to measure MSI stability. All RCTs had a low RoB. Subgroup analyses based on periotest indicated that MSIs treated with LLLT had significantly higher stability than untreated MSIs at 21 and 30 days [weighted mean difference (MD) = -2.76, confidence interval (CI) [-4.17, -1.36], P-value = 0.0001) and at 60 days (weighted MD = -3.47, CI [-4.58, -2.36], P < 0.00001); and the level of certainty was high. Subgroup analyses based on RFA showed higher stability of MSIs treated with than without LLLT at 56 and 60 days (standardized MD = 0.82, CI [0.32, 1.32], P = 0.001), and at 70 and 90 days (standardized MD = 0.86, CI [0.36, 1.36], P = 0.0007); and the level of certainty was moderate. LIMITATIONS: Due to limited number of relevant studies, it was not possible to perform sensitivity analysis, subgroup analyses for patient and intervention-related characteristics, and reporting biases assessment. CONCLUSIONS: The role of LLLT on the secondary stability of MSIs placed in patients undergoing OT remains debatable. CLINICAL TRIAL REGISTRATION PROSPERO (CRD42021230291).