Periodontal disease and systemic disease. Clinical information for the practicing dentist.

The relationship between periodontal and systemic disease, previously called the "focal infection theory" or "focus of infection," has become an exciting area of clinical and laboratory research. Periodontal disease has been reported to influence diabetes mellitus, cardiovascular disease, osteoporosis, and respiratory disease. It also can influence the course and duration of pregnancy. This article reviews some of these associations and proposed mechanisms by which periodontal disease and systemic conditions influence each other. We also discuss clinical implications for our daily practice in dentistry.