Effects of Non-Surgical Periodontal Therapy on Gingival Crevicular Fluid Levels of Interleukin-17 and Interleukin-23 in Patients with Periodontitis: A Clinical Trial

Background and Aim: Considering the critical role of inflammatory responses in periodontal disease, knowledge about the immune system and cytokines seems necessary. The aim of this study was to evaluate the level of IL-23 and IL-17 in gingival crevicular fluid (GCF) of patients with chronic and aggressive periodontitis, before and after non-surgical periodontal therapy. Materials and Methods: In the present clinical trial, GCF samples were collected from 54 patients (with aggressive and chronic periodontitis) before and after the initial phase of periodontal therapy. The cytokine concentration was measured using ELISA. The Wilcoxon signed-rank test was performed to analyze the effect of non-surgical periodontal therapy on each group. The correlation between variables was investigated by the Spearman’s correlation coefficient. Results: Non-surgical periodontal therapy in both groups significantly decreased the IL-17 and IL-23 levels (P<0.05). A significant correlation was noted between the concentration of IL-23 and IL-17 before the treatment in the chronic periodontal group (P<0.05), while such a correlation was not seen in the aggressive periodontitis group (P>0.05). Conclusion: Due to the reduction of IL-17 and IL-23 after nonsurgical periodontal therapy, these factors may play a role as mediators of periodontitis pathogenesis. Direct statistical correlation between the concentration of IL-17 and IL-23 before treatment in the chronic group shows the possible role of IL-23 in inducing Th-17 cells and production of IL-17.