TNF and chronic periodontitis: In a recent study, Reis et al. observed increased levels of inflammatory cytokines in periodontitis vs. healthy sites (pg/site), including interleukin 6 (IL-6) (0.13 vs 0.00), tumor necrosis factor-alpha (TNF-α) (0.06 vs. 0.01), interleukin 1α (IL-1α) (72.03 vs. 11.55), and interleukin 1β (IL-1β) (0.57 vs. 0.01) in the gingival crevicular fluid (GCF) of patients with chronic periodontitis who did not have any other underlying chronic systemic disorder [16].