Periodontal disease and cardiovascular disease: epidemiology and possible mechanisms.

BACKGROUND: Many early epidemiologic studies reported an association between periodontal disease and cardiovascular disease. However, other studies found no association or nonsignificant trends. This report summarizes the evidence from epidemiologic studies and studies that focused on potential contributing mechanisms to provide a more complete picture of the association between periodontal and heart disease. TYPES OF STUDIES REVIEWED: The authors summarize the longitudinal studies reported to date, because they represent the highest level of evidence available regarding the connection between periodontal disease and heart disease. The authors also review many of the case-control and cross-sectional studies published, as well as findings from clinical, animal and basic laboratory studies.
RESULTS: The evidence suggests a moderate association--but not a causal relationship--between periodontal disease and heart disease. Results of some case-control studies indicate that subgingival periodontal pathogenic infection may be associated with myocardial infarction. Basic laboratory studies point to the biological plausibility of this association, since oral bacteria have been found in carotid atheromas and some oral bacteria may be associated with platelet aggregation, an event important for thrombosis. Animal studies have shown that atheroma formation can be enhanced by exposure to periodontal pathogens.
CONCLUSIONS: The accumulation of epidemiologic, in vitro, clinical and animal evidence suggests that periodontal infection may be a contributing risk factor for heart disease. However, legitimate concerns have arisen about the nature of this relationship. These are early investigations. Since even a moderate risk contributed by periodontal disease to heart disease could contribute to significant morbidity and mortality, it is imperative that further studies be conducted to evaluate this relationship. One particularly important study to be carried out is the investigation of a possible clinically meaningful reduction in heart disease resulting from the prevention or treatment of periodontal disease.