BackgroundPeriostin, a secreted adhesion molecule, is a matricellular protein secreted most in periodontal ligament and periosteum. Periostin is also needed for integrity and maturation of periodontal tissue. This meta-analysis was conducted to compare the gingival crevicular fluid (GCF) periostin levels in subjects having periodontal disease and healthy periodontium.MethodsIn this meta-analysis, three international database including PubMed, Scopus and Web of Science were searched and 207 studies retrieved. Also, the Google Scholar was searched to find more related studies (two studies were found). To assess the risk of bias of included studies, the Newcastle–Ottawa assessment scale adapted for case–control was used. Finally, required data was extracted and included into analysis. All statistical analysis were done using Stata software.ResultsEight studies were included in this meta-analysis. Results showed that GCF periostin level is significant lower in chronic periodontitis group compare to healthy people (the standardized mean difference (SMD) = -3.15, 95% CI = -4.45, -1.85,p< 0.001). The syntheses of studies shown a significant decrease in the periostin level of chronic periodontitis patients compared to the gingivitis patients (SMD = -1.50, 95%CI = -2.52, -0.49,P= 0.003), while the mean level of periostin between the gingivitis patients and healthy group has no significant difference (SMD = -0.88, 95%CI = -2.14, 0.38, P = 0.173).ConclusionThe mean concentration of GCF periostin in people with chronic periodontitis significantly decreased compared to people with gingivitis and also compared to healthy people, while no significant difference was observed between the two groups with gingivitis and healthy people. Therefore, this marker may be used as a diagnostic criterion for the disease, which requires further studies.