Prevalence of Aggregatibacter actinomycetemcomitans and Periodontal Findings among 14 to 15-Year Old Danish Adolescents: A Descriptive Cross-Sectional Study

( ) is a keystone pathogen associated with periodontitis in adolescents. The knowledge on the prevalence of and periodontitis among adolescents in Northern Europe is sparse. A total of 525 14- to 15-year-old adolescents from the municipality of Aarhus, Denmark, underwent a full-mouth clinical examination. Plaque score (PS), bleeding on probing (BOP), probing pocket depth (PPD), and clinical attachment loss (CAL) were recorded. Subgingival plaque samples (SPS) and stimulated saliva samples (SSS) were collected and analyzed for the presence of JP2 and non-JP2 genotypes of using real-time PCR. A total of 70 (13.3%) individuals were positive for , with 17 found in SPS, 19 in SSS, and 35 in both. The highly leukotoxic JP2 genotype of was not detected. The individuals positive for in both SPS and SSS had poorer periodontal outcomes (PPD and CAL) than individuals without and individuals carrying in either SPS or SSS only. In conclusion, 13% of 14- to 15-year-old Danish adolescents were positive for , and the presence of in both SPS and SSS was associated with poorer periodontal outcomes.