Association between periodontitis and the development of systemic diseases

Periodontal diseases, common infectious diseases seen in humans, are characterized by gingival inflammation and a loss of connective tissue and bone around the roots of teeth, which leads to eventual tooth exfoliation. In the past decade, the association between periodontal diseases and the development of systemic diseases has received increasing attention. Periodontal pathogens and their products, as well as inflammatory mediators produced in periodontal tissues, can enter the bloodstream, thereby causing and/ or contributing to the development of systemic diseases. A variety of recent studies have compiled various results showing that periodontal infections are implicated in the development of various systemic diseases. This review summarizes the evolution of the focal infection theory to the current understanding of the pathophysiology of periodontal disease and presents an update of the mechanisms and relationships between chronic periodontitis and systemic diseases, including cardiovascular diseases, respiratory infections, preterm delivery of low-birth-weight fetuses and diabetes mellitus.