Periodontal health during orthodontic treatment with clear aligners and fixed appliances A meta-analysis

Background. Clear aligners have become increasingly popular because of their esthetics and comfort. The authors' aim in this systematic review was to compare periodontal health in patients undergoing orthodontic treatment with clear aligners with that of those undergoing orthodontic treatment with fixed appliances.Types of Studies Reviewed. The authors systematically searched the PubMed, Web of Science, Cochrane Library, and Embase databases to collect related studies. After extracting data and assessing quality, the authors performed a meta-analysis and trial sequential analysis. The authors used the Grading of Recommendations Assessment, Development and Evaluation system to assess the quality of the evidence.Results. The authors included 9 studies in the quantitative synthesis analysis. Clear aligners were better for periodontal health, including plaque index (mean difference [MD], -0.53; 95% confidence interval [CI], -0.85 to -0.20; P = .001), gingival index (MD, -0.27; 95% CI, -0.37 to -0.17; P < .001), and probing depth (MD, -0.35; 95% CI, -0.67 to -0.03; P = .03), than were fixed appliances. However, the trial sequential analysis outcome indicated a false-positive meta-analysis result for probing depth. The authors downgraded the level of the evidence because of the risk of bias and inconsistency.Conclusions and Practical Implications. Clear aligners were better for periodontal health than fixed appliances and might be recommended for patients at high risk of developing gingivitis. However, high-quality studies still are required.