IL17A and periodontitis: This study also showed comparable results to Vernal et al. [12] who reported significantly higher total amounts of IL-17 in GCF and in the culture supernatants of GCP patients than in C. Elevated tissue concentrations of IL-17 could promote periodontitis progression by increasing concentrations of bone resorbing chemokines, which suggests that IL-17 may be a mediator of periodontal destruction [12, 25].