TNF and periodontitis: Periodontitis is a chronic or acute condition of the tissues surrounding the tooth of complex etiology, which is the cause of the local and general increase in inflammatory mediators and immune complexes, such as C-reactive protein (CRP), fibrinogen, nitric oxide (NO), interleukin 1 (IL-1), interleukin 6 (IL-6), and tumor necrosis factor (TNF-α) [30].