title: Searching for Helicobacter pylori and Chlamydia pneumoniae in primary endodontic infections.
abstract: OBJECTIVE
  The purpose of this study was to search samples from primary endodontic infections for the presence of two common human bacterial pathogens - Helicobacter pylori and Chlamydia pneumoniae.
  
  
  METHODS
  Genomic DNA isolated from samples taken from 25 root canals of teeth with asymptomatic (chronic) apical periodontitis and 25 aspirates from acute apical abscess was initially amplified by the multiple displacement amplification approach and then used as template in species-specific polymerase chain reaction (PCR) for detection of H. pylori and C. pneumoniae.
  
  
  RESULTS
  All clinical samples were positive for the presence of bacterial DNA. However, no clinical sample was positive for either H. pylori or C. pneumoniae.
  
  
  CONCLUSIONS
  Neither H. pylori nor C. pneumoniae were found in samples from primary endodontic infections. These findings suggest that these species are not candidate endodontic pathogens and that the necrotic root canal does not serve as a reservoir for these human pathogens in healthy patients.
authors.affiliation: Department of Endodontics and Molecular Microbiology Laboratory, Faculty of Dentistry, Estácio de Sá University, Rio de Janeiro, RJ, BRAZIL.
authors.forename: Isabela N
authors.initials: IN
authors.lastname: Rôças
authors.forename: José F
authors.initials: JF
authors.lastname: Siqueira