In the peri-implantitis group, it was found that the mean ± SD value in these cases with the (GG), (GA) and (AA) genotype was (609.02 ± 102.14), (609.09 ± 69.18) and (639.78 ± 176.51) respectively, there were no significant differences between genotypes of IL-17A and PISF levels of IL-23 (p = 0.921). The gene discussed is IL17A; the disease is Peri-Implantitis.