TNF and periodontal disorder: The main pathogenic factors in periodontal disease such as periodontopathic bacteria, fimbriae, proteases and endotoxins, act on monocytes, macrophages, gingival fibroblasts, IL-1β, IL-6, IL-8, PGE2, tumor necrosis factor-α, chemokine (CC-motif) ligand 5 and MMPs to induce inflammatory reactions and cell damage through a complex cytokine network and eventually alveolar bone destruction progresses [23].