IFNG and Peri-Implantitis: Similar to our results, Fonseca et al. reported that there were no differences between patients with mucositis and those with peri-implantitis in levels of IL-1β, IL-2, IL-4, IL-5, IL-6, IL-7, IL-8, IL-10, IL-12, IFN-γ, or TNF-α in saliva [30].