Detecting Oral Bacteria in Abdominal Aorta Atherosclerotic Plaques—How Far Can They Go?

<i>Background and objectives</i>: Atherosclerotic cardiovascular disease (ASCVD) remains a major global cause of mortality, with chronic infections and systemic inflammation, including those arising from periodontal pathogens, contributing to vascular pathology. This study aims to investigate the presence of bacterial DNA from oral cavity microorganisms in atherosclerotic plaques of patients with abdominal aortic aneurysm (AAA) and to explore correlations with oral health indices and clinical variables. <i>Materials and Methods</i>: Forty patients (mean age 61 ± 6 years; 60% male) with periodontitis and AAA were included. Subgingival biofilm and arterial plaque samples were analyzed using PCR for <i>A. actinomycetemcomitans</i>, <i>P. gingivalis</i>, <i>P. intermedia</i>, <i>T. forsythensis</i>, and <i>T. denticola</i>. Dental indices (PI, GI, SBI, and PPD) were determined in all patients, and concordance of the findings was assessed by Cohen's κ, and correlations were evaluated using Spearman's coefficient. <i>Results</i>: <i>P. gingivalis</i> exhibited the highest concordance between oral and arterial plaques, followed by <i>T. forsythensis</i> and <i>A. actinomycetemcomitans</i>. <i>T. denticola</i> DNA was not detected in aortic samples. Positive correlations found between <i>A. actinomycetemcomitans</i> and <i>P. gingivalis</i> with dental indices were found to be statistically significant. <i>Conclusions</i>: The detection of periodontal pathogens, particularly <i>P. gingivalis</i> and <i>T. forsythensis</i>, in both oral and arterial plaques supports their potential role in atherosclerotic and aneurysmal changes. The findings highlight the relevance of periodontal health in cardiovascular risk prevention and the need for longitudinal studies to reveal causal mechanisms.