In this context, T2DM intensifies the inflammatory response in periodontal tissues [70], leading to an increase in the expression of inducible nitric oxide synthase (iNOS) and in the levels of lipid peroxides [71] and proinflammatory mediators, such as prostaglandin (PG)-E2, TNF-α, IL-1β, IL-6, IL-17, and, IL-23, in periodontal tissues and in gingival crevicular fluid (GCF) [72], which contributes to a more severe course of periodontal inflammation [73,74,75]. This evidence concerns the gene NOS2 and type 2 diabetes mellitus.