title: Periopathogenic bacteria in persistent periapical lesions: an in vivo prospective study.
abstract: BACKGROUND
  The aim of this in vivo prospective study was to detect the presence of periopathogenic bacteria in persistent periapical lesions and to compare the reliability of two different methods: anaerobic culture and the DNA hybridization technique.
  
  
  METHODS
  Samples were obtained from 24 patients with persistent periapical lesions referred for surgical endodontic treatment. A sterile paper point was inserted into the periapical lesion for 10 seconds. The point was stored in sterile transfer tubes and analyzed by DNA hybridization. Tissue samples were transported in transfer medium and analyzed further using anaerobic culture.
  
  
  RESULTS
  At least one periodontal pathogenic bacterium was found in seven of 24 cases. Bacterial species present were Treponema denticola (three cases), Porphyromonas gingivalis (three cases), Tannerella forsythensis (four cases), Prevotella intermedia (one case), and Actinobacillus actinomycetemcomitans (three cases). No particular signs or symptoms were associated with the presence of these bacterial species. Anaerobic culture failed to identify any of the periopathogenic bacteria.
  
  
  CONCLUSIONS
  Periodontal pathogenic bacterial DNA can be detected in persistent periapical lesions. Anaerobic cultures failed to detect the periodontal pathogenic bacteria in positive hybridization assays, suggesting that standard culture methods lack sensitivity or that hybridization assays are flawed with low specificity. The clinical significance of the presence of bacterial DNA in persistent periapical lesions remains to be determined.
authors.affiliation: Endodontics and Dental Trauma Unit, Department of Oral and Dental Medicine, Rambam Medical Center, Haifa, Israel. linsh@post.tau.ac.il
authors.forename: Shaul
authors.initials: S
authors.lastname: Lin
authors.forename: Galit
authors.initials: G
authors.lastname: Sela
authors.forename: Hannah
authors.initials: H
authors.lastname: Sprecher
mesh_terms: D000293:Adolescent; D000328:Adult; D015373:Bacterial Typing Techniques / Q000379:methods*; D002908:Chronic Disease; D015169:Colony Count, Microbial; D004269:DNA, Bacterial / Q000032:analysis*; D005260:Female; D006089:Gram-Negative Anaerobic Bacteria / Q000235:genetics / Q000302:isolation & purification*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009693:Nucleic Acid Hybridization / Q000379:methods*; D010485:Periapical Periodontitis / Q000382:microbiology* / Q000473:pathology; D011446:Prospective Studies; D011933:Reagent Kits, Diagnostic; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D004269:DNA, Bacterial; D011933:Reagent Kits, Diagnostic