IL17A and Peri-Implantitis: Proinflammatory cytokines (IL-1β, TNF-α, IL-6, IL-17 and IL-12) play an important role in the initiation and progression of inflammatory diseases, and elevated crevicular concentrations of these proinflammatory biomarkers have been associated with peri-implantitis, especially IL-1β, which has been identified as a major contributor to bone loss, and elevated levels of IL-1 β in saliva are considered to reflect a local inflammatory response in peri-implant tissues (48, 49).