The annual increase in the incidence of diabetes and frequency of its complications determine the urgency of this problem. The most characteristic sighns of diabetes are vascular lesions of arterioles, venules, capillaries (microangiopathy). Changes in microcirculatory system at diabetes mellitus leads to other complications. The pathology of the marginal periodontium in patients with diabetes is, in fact, a local manifestation of diabetes-specific microangiopathy, which causes degenerative changes in periodontal tissues.