Relationship between diabetes mellitus (DM) and periodontal disease has been the subject of many studies that underline that diabetic patients are two/three times more susceptible to have an increased risk of periodontal disease, especially when metabolic control is inadequate. In this review the authors analyze, in diabetic patient, biochemical, histological and microbiological aspects of periodontal disease. Recent studies reported the results obtained in not diabetic patients, both periodontopatic and not: in periodontopatic subjects, the value of glycated hemoglobin was higher. As regards type 2 DM has a positive relationship between periodontal inflammation and glycemia, with good probabilities of disease development. Some Authors show...