Type 2 diabetes mellitus has been described as a new epidemic. Approximately 285 million people worldwide suffer from diabetes, and this number is predicted to increase by approximately 50% by year 2030. This article will review oral health manifestations of diabetes and discuss associations between periodontal disease and diabetes. Although there is a strong body of evidence that supports the relationship between oral health and type 2 diabetes mellitus, oral health awareness is lacking among patients with diabetes and other health professionals. There is a need for the treating physician to be educated about the various oral manifestations of diabetes so that they can be diagnosed early and timely referrals to oral health specialists can be made. The established link between periodontitis and diabetes calls for an increased need to study ways to control both diseases, particularly among populations with health disparities and limited access to oral and health care.