Periodontal pathogens in atheromatous plaques. A controlled clinical and laboratory trial

A possible relationship between periodontitis and cardiovascular disease has been suggested. The aims of this controlled clinical study were: (i) to ascertain the presence of periodontal bacteria DNA [Actinobacillus actinomycetemcomitans, Fusobacterium nucleatum, Porphyromonas gingivalis, Prevotella intermedia, Tannerella forsythensis (formerly Bacteroides forsythus)] in carotid atheromatous plaques and (ii) to assess the concomitant presence of the same periodontal bacteria DNA, if any, in periodontal pockets and in carotid atheroma in the same patient.

A total of 52 patients scheduled for carotid endarderectomy were enrolled in this study. The test group consisted of 26 dentate patients; the control group included 26 edentulous patients. A complete periodontal examination, including radiographic orthopanoramic and subgingival plaque sample, was performed in the test population. Oral and X-ray examinations were performed in the control group. Atheromatous plaques were harvested during surgical procedure for each dentate and edentulous patient and then sent to the microbiological laboratory. Subgingival plaque samples and carotid specimens were examined using the polymerase chain reaction (PCR) technique by means of specific primers for periodontal bacteria. Amplification of extracted DNA was tested using human beta-globin specific-primers.

Out of 52 endarterectomy samples, 12 (seven dentate, five edentulous patients) were excluded as negative to DNA amplification. In subgingival plaque samples of 19 test patients, T. forsythensis (79%), F. nucleatum (63%), P. intermedia (53%), P. gingivalis (37%) and A. actinomycetemcomitans (5%) were found. No periodontal bacteria DNA was detected by PCR in any of the carotid samples in either patient group.

The presence of periodontal bacteria DNA in atheromatous plaques could not be confirmed by this study and thus no correlation could be established between species associated with periodontal disease and putative bacteria contributing to atheromatous plaques.