In animal experiments, the mRNA expression of IL-1β, IL-6, and TNF-α in rats with simple periodontitis was 2.63 times, 2.79 times, and 4.18 times higher than those in healthy rats, and the mRNA expression of these cytokines in rats with diabetes increased by 1.78 times, 1.58 times, and 3.04 times, respectively. This evidence concerns the gene TNF and diabetes mellitus.