Abstract: Its a fact that about 5% of the world’s population is affected by diabetes. The term "diabetes mellitus "is a group of certain disorders, such as fat and protein metabolism, high glucose levels, and abnormalities of carbohydrate that characterize these disorders. The number of infected patients is predicted and expected to rise by 50% by the year 2030. The review article discusses the associations between diabetes and periodontal disease and the oral health manifestation of diabetes. There is a lack of oral health awareness among health professionals and even patients infected with diabetes. There is strong evidence supporting the relationship between diabetes and oral health. Diabetes mellitus is associated with several disorders and oral diseases. Periodontitis is a risk factor in subject with diabetes for poor metabolic control. Thus, the authors reviewed the literature to identify why diabetes causes oral conditions.