Serum levels of proinflammatory cytokines was also measured before periodontitis induction and they were higher in rats with dHPT (15.75 ± 0.49 vs. 10.12 ± 0.92 pg/m, for IL-1β and 176.75 ± 23.06 vs. 13.02 ± 1.38 pg/mL for TNF-α, p < 0.001). This evidence concerns the gene TNF and periodontitis.