Molecular epidemiology and association of putative pathogens in root canalinfection

The purpose of this study was to investigate the epidemiology of putative p athogens in root canals with apical periodontitis and to determine the asso ciations among the putative pathogens. Eighteen symptomatic and 20 asymptom atic teeth from 36 subjects were studied. This research was performed with polymerase chain reaction and hybridization using rRNA-based oligonucleotid e probes. The most frequently found species was Fusobacterium sp. (68.4%), followed by Peptostreptococcus micros (44.7%) and Porphyromonas gingivalis (26.3%). Sixteen teeth (42.1%) contained one or more species of the selecte d black-pigmented bacteria. Bacteroides forsythus and Treponema sp. were de tected in 8 teeth and 6 teeth, respectively. Among the analyzed bacteria, s ignificant relationships were shown in the combination of B. forsythus/P. g ingivalis and Treponema sp./P. gingivalis. There was no significant associa tion between any bacteria and any symptoms.