Three case reports of aggressive periodontitis associated with Porphyromonas gingivalis in younger patients.

The terms 'early onset periodontitis' (EOP) and 'juvenile periodontitis' (JP) were replaced by that of 'aggressive periodontitis' in a recent international workshop for the classification of periodontal diseases and conditions. The chief etiologic agent for aggressive periodontitis is considered to be Actinobacillus actinomycetemcomitans in localized juvenile periodontitis. Porphyromonas gingivalis is also mentioned as the etiologic agent of the aggressive periodontitis, although to date its role remains questionable. This communication describes three cases of aggressive periodontitis found to be associated with P. gingivalis but not A. actinomycetemcomitans by polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay (ELISA). Our findings clarify the role of P. gingivalis as an etiologic agent in this type of periodontitis and confirm its inclusion in the current definition of aggressive periodontitis.