The association between periodontal disease and cardiovascular disease has been described in many studies; however, many have looked at periodontal disease only by examining clinical parameters, such as gingival bleeding, dental x-rays, depth of periodontal pockets, and others. Periodontal disease can also be evaluated by various biological markers, such as bacterial exposure, level of antibodies against periodontal microorganisms, and levels of various body chemicals which are known markers of inflammation.

Three measures of bacterial systemic exposure were used in this analysis: bacterial burden of gingival plaque; C-reactive protein levels (CRP) which represent the innate immune response; and serologic markers which represent the acquired immune serologic response, specifically antibodies against Porphyromonas gingivalis (Pg) and Actinobacillus actinomycetemcomitans (Aa). Two cardiovascular end points were used as outcome measures, and included both cardiovascular events and carotid intima-media thickness. The results suggest that periodontal disease associated with elevated levels of systemic markers of bacterial exposure are more strongly associated with coronary heart disease (CHD) than has been previously reported, with an odds ratio of 1.75. The authors note that this association begins to build the case for causality, especially since the cohort studies selected for the review demonstrate the proper time sequence. In addition, the authors explain that the association between CHD and periodontal disease is biologically plausible because CRP, Pg, and Aa have been detected within inflamed atheromatous plaques, and molecular pathways to initiate and sustain atheroma progression have been identified.

With more and more studies emphasizing the importance of infectious "exposure" rather than the periodontal status, this investigation's focus on systemic bacterial exposure, in addition to periodontal disease, makes a very important distinction. Frequency and severity of systemic bacterial exposure from the oral cavity are critically important to overall health, even in cases where obvious periodontal pathology may not be evident. This may be the most important determinant of inflammatory associations with systemic diseases.