Epidemiological studies indicated that more than 15% of the population in western countries suffer because of severe forms of periodontitis, In this respect, the recognition of the relationship between oral and systemic health is growing, thus receiving remarkable interest in scientific literature. In fact, periodontitis may increase the risk for a group of life-threatening conditions such as atherosclerosis, stroke or low birth weight. The American Diabetes Association has reported that individuals with uncontrolled diabetes (defined as 200mg/dL of glucose on three consecutive readings) undergo an increased risk of infections, abnormal wound healing and consequent increased recovery time. Moreover, diabetics may be more likely to develop periodontal and cardiovascular disease than non diabetics, if note. History of poorly controlled chronic periodontal disease can alter diabetic/glycemic control. This may originate from a likely continuous passage of bacterial toxins and/or bacteria into the bloodstream, and/or from an exaggerated release of inflammatory mediators. This review is aimed at elucidating the connections between the status of oral health and glycemic control in diabetes.