Objective To explore the similarities and differences of the expression of interleukin（IL）-17 and 23 between the group of peri-implantitis and peri-implantar healthy patients. To determine the effect and mutual relations of IL-17 and 23 in the development and progression of peri-implantitis. Methods Implant cases were divided into health-implant group and peri-implantitis group, the health of natural teeth of the opposite side with the same name as the control group. The peri-implant sulcular fluid were collected to determine the concentration of IL-17 and IL-23 by using enzyme-linked immunosorbent assay method. Results In the peri-implant sulcular fluid of the peri-implantitis, the concentration of IL-17 and 23 was significantly higher than that in the implant group（P
