Detection of Porphyromonas endodontalis in infected root canals by 16S rRNA gene-directed polymerase chain reaction

Porphyromonas endodontalis has been isolated from the endodontic infections mainly in symptomatic teeth. This study evaluated the occurrence of P. end odontalis in both symptomatic and asymptomatic endodontic infections using 16S rRNA gene-directed polymerase chain reaction. P. endodontalis was detec ted in 39.5% of the cases (17 of 43 teeth). It was present in 4 of the 6 ca ses with acute periradicular abscess (66.7%) and in 13 of the 37 other case s (35.1%). The presence of P. endodontalis was associated with an asymptoma tic periradicular lesion in 6 cases (25%) and in 10 teeth with tenderness t o percussion (52.6%). P. endodontalis was also found in one asymptomatic ca se without evidence of periradicular pathosis. Our results indicated that, although P. endodontalis is commonly detected in symptomatic cases, it can be present in asymptomatic root canal infections. Further studies should de termine if this bacterial species is really an important endodonto-pathogen .