title: Analysis of symptomatic and asymptomatic primary root canal infections in adult Norwegian patients.
abstract: BACKGROUND
  This molecular study analyzed the microbiota of primary root canal infections from adult Norwegian patients.
  
  
  METHODS
  Samples were taken from the necrotic root canals of teeth with symptomatic (n = 13) or asymptomatic (n = 21) apical periodontitis and chronic apical abscesses (n = 9). DNA was extracted from samples, and bacterial identifications were performed by a closed-ended reverse-capture checkerboard approach targeting 50 candidate endodontic pathogens.
  
  
  RESULTS
  Bacterial DNA was detected in all cases. In teeth with asymptomatic apical periodontitis, the most frequent taxa were Dialister invisus (71%), Fusobacterium nucleatum (62%), and Porphyromonas endodontalis (62%). In chronic apical abscesses, the most prevalent taxa were P. endodontalis (100%), D. invisus (89%), Parvimonas micra (78%), and Solobacterium moorei (78%). In teeth with symptomatic apical periodontitis, the most prevalent taxa were D. invisus, P. endodontalis, S. moorei, Propionibacterium acnes, and Streptococcus species (all in 69%). None of the targeted taxa were significantly associated with either sinus tract or pain (P > .05), except for Selenomonas sputigena, which was more frequently found in painful cases (P = .04). No taxa were found in significantly higher levels in any conditions (P > .05). Cluster analyses revealed bacterial groupings that differed between cases with and without pain.
  
  
  CONCLUSIONS
  Although basically the same species were highly prevalent in the different conditions examined and none of the most prevalent taxa were positively associated with symptoms, results revealed that species formed different partnerships and associations in samples from teeth with or without pain. Therefore, it is possible that more virulent multispecies communities can form as a result of overall bacterial combinations and give rise to acute inflammation.
authors.affiliation: Department of Endodontics and Molecular Microbiology Laboratory, Estácio de Sá University, Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Isabela N
authors.initials: IN
authors.lastname: Rôças
authors.forename: José F
authors.initials: JF
authors.lastname: Siqueira
authors.forename: Gilberto J
authors.initials: GJ
authors.lastname: Debelian
mesh_terms: D000328:Adult; D058345:Asymptomatic Infections; D016009:Chi-Square Distribution; D016000:Cluster Analysis; D004269:DNA, Bacterial / Q000032:analysis; D003790:Dental Pulp Necrosis / Q000382:microbiology*; D006801:Humans; D009664:Norway; D009693:Nucleic Acid Hybridization / Q000379:methods; D010482:Periapical Abscess / Q000382:microbiology; D010485:Periapical Periodontitis / Q000382:microbiology; D012390:Root Canal Therapy; D018709:Statistics, Nonparametric; D037521:Virulence Factors
chemical_list: D004269:DNA, Bacterial; D037521:Virulence Factors