Periodontal disease is considered as the 6th complication of Diabetes mellitus. Periodontal disease  is a chronic inflammatory condition characterized by destruction of the periodontal tissues and resulting in loss of connective tissue attachment, loss of alveolar bone and the formation of pathological pockets around the  diseased teeth. Periodontal disease is more prevalent and more severe in persons with diabetes than in non diabetic individuals.

There is emerging evidence to support the existence of a two way relationship between diabetes and periodontitis, with diabetes increasing the risk for periodontitis and periodontal inflammation negatively affecting glycemic control. Periodontal disease is also associated with heart disease. Research indicates that inflammation caused by periodontal disease may be responsible for the increase in risk of heart disease. Periodontal disease can also exacerbate existing heart conditions. Studies have also pointed out a relationship between periodontal disease and stroke.