TNF and periodontitis: Nowadays, the field of research regarding oral markers, especially inflammatory mediators such as cytokines and chemokines, has advanced significantly [91], and a wide variety of them have been used in the diagnosis of patients with periodontitis, as is the case with TNF-α [98], CXCL10, IL-6, CXCL13, IL-8, IFN-γ, IL-10 [99], IL-18 [100], IL-21 [101] and the IL-23/IL-17 axis [102].