Health sciences are in the midst of major transition. The oral cavity contains almost half the commensal bacteria in the human body, approximately six billion microbes. The oral cavity is remarkably dynamic and continuously challenged by opportunistic infection on one hand and the oral complications of systemic diseases on the other. Periodontitis is an oral disease with documented risk factors including smoking, specific plaque bacteria, diabetes mellitus, hypertension, etc. While this link between systemic disease and periodontitis was thought to be unidirectional, mounting evidence in the last decade suggests that the relationship may be bi-directional. Therefore, oral health is an important component of general health and individuals with periodontitis may be at risk for other diseases as well. The association between diabetes and periodontal diseases has long been discussed with conflicting conclusions. The present paper discusses the bidirectional relationship between periodontitis and diabetes mellitus.
