Assessment of the periodontal health status in patients undergoing orthodontic treatment with fixed appliances and Invisalign system: A meta-analysis

Background:At present, many scholars have studied the periodontal health status of patients undergoing orthodontic treatment with fixed appliances and invisalign. However, those results are inconsistent. Therefore, we conducted this meta-analysis, and then provide reference for clinical treatment.Methods:Most databases, such as the Cochrane Library, EMBASE, PubMed, Medline, Chinese Biomedical Literature Database, CNKI, and Wan Fang Data were retrieved for related articles from the establishment of the database to October 2017. Meanwhile, we also searched the references of the related literatures manually, in order to increase the included literatures. Two researchers screened the related literatures according to the inclusion criteria and exclusion criteria. Stata 12.0 software was used for data analysis, and results are estimated by odds ratio (OR) and 95% confidence interval (CI).Results:Finally, 7 articles, including 368 patients, were included into our meta-analysis. Meta-analysis results showed that there was no statistically significant difference of gingival index (GI) and sulcus probing depth (SPD) status between the invisalign group and the control group, including at 1, 3, and 6 months (all P>.05). When compared with the control group, the invisalign group presented a lower plaque index (PLI) and sulcus bleeding index (SBI) status at 1 month (OR=-0.53, 95% CI: -0.89 to -0.18; OR=-0.44, 95% CI: -0.70 to -0.19, respectively), 3 months (OR=-0.69, 95% CI: -1.12 to -0.27; OR=-0.49, 95% CI: -0.93 to -0.05, respectively), and 6 months (OR=-0.91, 95% CI: -1.47 to -0.35; OR=-0.40, 95% CI: -0.63 to -0.07, respectively). Subgroup analysis showed that the SPD status was lower in the invisalign group at 6 months when measured the teeth using Ramfjord index (OR=-0.74, 95% CI: -1.35 to -0.12). However, there was no statistically significant difference between the 2 groups when using other measure methods (OR=0.12, 95% CI: -0.26 to 0.17).Conclusion:Our meta-analysis suggests that comparing with the traditional fixed appliances, patients treated with invisalign have a better periodontal health. However, more studies are needed to confirm this conclusion in the future.