TNF and Peri-Implantitis: In particular, proinflammatory cytokines (e.g. TNF-α, IFN-γ, IL-1β, IL-6, IL-12, IL-17, and receptor activator of nuclear factor κB (NF-κB) ligand (RANKL)), anti-inflammatory cytokines (e.g. IL-4 and IL-10) and chemokines (e.g. IL-8, monocyte chemoattractant protein-1, and macrophage inflammatory protein-1α) have been suggested to be important mediators of inflammation and immunity during the pathogenesis of peri-implantitis [5–9].