TNF and periodontitis: DM1 patients with periodontitis showed higher fibrinogen (371.3 ± 114.7, p < 0.01) and TNF-α (1.6 ± 1.2, p < 0.001) concentrations, as well as lower OHI (2.1 ± 0.7, p < 0.001) and a lower number of teeth (p < 0.001).