This case-control study evaluated the periodontal condition of patients diagnosed with coronary artery disease (CAD). The authors of this article based their investigation around the concept that chronic periodontal infection may have a direct or indirect impact on a patient’s cardiovascular status. Several studies have been cited that demonstrate the association between the two, but there is a lack of agreement among researchers on a conclusion of cause and effect. The goal of this study was to try to observe a clear association between CAD and the organisms found in patients with periodontal disease. The study was particularly ambitious in that it sought to link not just certain bacterial types to CAD, but bacterial burden as well.

The investigators collected clinical periodontal data and used a state-of-the-art methodology – real-time polymerase chain reaction – to determine if Actinobacillus actinomycetemcomitans, Prophyromonas gingivalis, Provetella intermedia, Parvimonas micra, Dialister pneumosintes and Campylobacter rectus were different in the subgingival pockets of subjects with and without CAD. In molecular biology, the real-time polymerase chain reaction is a technique that can amplify and quantify a specific part of the DNA molecule. The technique will reveal if a specific DNA sequence (i.e., a specific bacterium) is present, as well as how many copies of that DNA sequence are present.

With regard to microbiota, there were no differences in the putative periodontal pathogens, except for higher concentrations of Provetella intermedia found in the gingival pockets of subjects with CAD when compared to healthy control subjects, suggesting that P. intermedia may be the common organism involved with both diseases. The investigators further observed that subjects with CAD had deeper probing depths (approximately 0.7 mm deeper) and more attachment loss (approximately 0.8 mm more loss) than controls, even after adjusting for smoking; i.e., patients with CAD have more periodontitis. While this is not a new finding, it is nonetheless confirmatory.

Overall, the findings of the study reaffirm that there may be an association between periodontal disease and CAD. Unfortunately, the biologic mechanism has not yet been established, suggesting a need for further, well-defined clinical investigations.