title: [Association between Bacteroides forsythus in the infected root canals and clinical symptoms of chronic apical periodontitis].
abstract: OBJECTIVE
  To investigate the distribution of Bacteroides forsythus in root canals with chronic apical periodontitis and to determine its associations with clinical symptoms.
  
  
  METHODS
  Thirty-eight tooth root canals from 31 subjects were studied with a 16S rDNA-directed polymerase chain reaction (PCR). These teeth were classified into symptomatic and asymptomatic groups according to the clinical symptoms and signs, including spontaneous pain, percussion pain, sinus tract and swelling, respectively.
  
  
  RESULTS
  Ten of the 38 root canal samples were positive for B. forsythus. The prevalence of B. forsythus was 26.3% for 38 root canals, 45.5% for spontaneous pain group, 39.1% for percussion pain group, 29.4% for sinus tract group, 42.9% for swelling group, respectively. Significant positive associations were observed between B. forsythus in infected root canals and the spontaneous pain, percussion pain, and swelling of apical periodontitis, respectively (OR=infinity, 9, 12; P<0.05). There was no significant association between B. forsythus and sinus tract of apical periodontitis (OR=1.33).
  
  
  CONCLUSIONS
  B. forsythus colonized in the infected root canals. It is the putative pathogen of apical periodontitis.
authors.affiliation: Department of Endodontics, West China School of Stomatology, Sichuan University, Chengdu 610041, China.
authors.forename: Ding-ming
authors.initials: DM
authors.lastname: Huang
authors.forename: Chun-hua
authors.initials: CH
authors.lastname: Fu
authors.forename: Xue-dong
authors.initials: XD
authors.lastname: Zhou
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001439:Bacteroides / Q000145:classification / Q000302:isolation & purification*; D001442:Bacteroides Infections / Q000382:microbiology*; D002648:Child; D002908:Chronic Disease; D004269:DNA, Bacterial / Q000032:analysis; D003786:Dental Pulp Cavity / Q000382:microbiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010485:Periapical Periodontitis / Q000382:microbiology*; D016133:Polymerase Chain Reaction; D011671:Pulpitis / Q000382:microbiology*; D012336:RNA, Ribosomal, 16S / Q000032:analysis
chemical_list: D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S