Comparative impact of clear aligners versus fixed orthodontic appliances on periodontal health, pain, and quality of life: a systematic review and meta-analysis.

Abstract

Objective: Clear aligners have become a popular alternative to fixed appliances because they offer esthetic advantages and potential improvements in periodontal health and pain management while enhancing quality of life (QOL). This systematic review and meta-analysis investigated the effects of clear aligners versus fixed appliances on established outcomes.

Materials and methods: A systematic search was conducted in PubMed, Scopus, Cochrane Library, Embase, and ScienceDirect up to March 2025, along with gray literature and manual searching of key orthodontic journals. The eligible studies consisted of randomized controlled trials and observational studies that evaluated clear aligners against fixed appliances based on the plaque index (PI), gingival index (GI), probing depth (PD), pain intensity, and QOL. Researchers applied mean difference (MD) to PI, GI, and PD, while standardized mean difference (SMD) was used to evaluate pain intensity and QOL. Researchers evaluated heterogeneity using I² and publication bias while performing subgroup analyses centered on treatment duration.

Results: Thirty-two studies were included in the systematic review, of which 28 were included in the meta-analysis. Clear aligners significantly improved periodontal outcomes compared to fixed appliances, as shown by lower PI scores (MD = -0.437, 95% CI: -0.507 to -0.367, p < 0.001), GI scores (MD = -0.233, 95% CI: -0.296 to -0.170, p < 0.001), and PD scores (MD = -0.332, 95% CI: -0.431 to -0.234, p < 0.001). Patients treated with clear aligners experienced less pain than those treated with fixed appliances, particularly during the early treatment phase (SMD = -0.419, p < 0.001). Clear aligners significantly improved the QOF of patients at 1 week (SMD = -0.985, p < 0.001), 1 month (SMD = -0.829, p < 0.001), and end of treatment (SMD = -0.970, p < 0.001) compared with fixed appliances. Low to moderate heterogeneity was observed between groups for pain outcomes, while high heterogeneity was observed for short-term QOF comparisons.

Conclusion: Clear aligners resulted in favorable periodontal indices compared with those of fixed appliances. They also led to less early pain and better QOF than fixed appliances, although these differences were mostly observed at the beginning of treatment. Clinicians should interpret these results cautiously because of heterogeneity, the inclusion of observational evidence, potential publication bias, and small pooled effects.