Tannerella forsythia detected in infected root canals using nested PCR.
PURPOSE This study assessed the occurrence of Tannerella forsythia in patients with acute and chronic primary endodontic infections. METHODS Clinical samples were collected from 40 patients with acute and chronic periradicular disease. Nested polymerase chain reaction (PCR) assay technique was used to detect the presence of T. forsythia in primary endodontic infections. The first round of PCR amplification used universal primers to detect the 16S rDNA sequence. Product from the first round was then used to amplify T. forsythia specific fragment with species-specific pairs of primers. RESULTS T. forsythia was found in 12 of 27 chronic and 5 of 13 acute infected patients for an overall occurrence frequency of 42.5%. No significant correlation was found between patients with the T. forsythia positive genotype and the occurrence of clinical symptoms in the primary endodontic infections (P < 0.05) (P = 0.496). Also, no significant relationship was found between the occurrence of T. forsythia and the patient's age (P = 0.61) or gender (P = 0.239).