title: Surgical endodontic treatment of refractory periapical periodontitis with extraradicular biofilm.
abstract: OBJECTIVE
  This study explored the effect of surgical endodontic treatment of refractory periapical periodontitis with extraradicular biofilm.
  
  
  METHODS
  Endodontic surgery was conducted on a case of refractory periapical periodontitis with extraradicular biofilm. During the procedure, the samples of periapical tissues were collected for microbiologic analysis. The resected root ends were observed under scanning electron microscope. The patient was recalled every 3 months to evaluate the treatment effect for 1 year.
  
  
  RESULTS
  The samples yielded 1 type of facultative anaerobic bacteria (Streptococcus sanguis) and 2 types of obligate anaerobic bacteria (Porphynomonas endodontalis and Prevotella oralis). Mature bacteria biofilms were formed on the surface of the root apexes. At the 1-year recall visit, the radiograph and the clinic examination showed the refractory periapical periodontitis was cured successfully.
  
  
  CONCLUSIONS
  The periapical bacterial biofilm may contribute to the refractory periapical periodontitis. Endodontic surgery is a good option for definitive removal of an established extraradicular infection.
authors.affiliation: Department of Operative Dentistry and Endodontics, School of Stomatology, Fourth Military Medical University, Xi'an, China.
authors.forename: Lingyun
authors.initials: L
authors.lastname: Su
authors.forename: Yang
authors.initials: Y
authors.lastname: Gao
authors.forename: Chengjun
authors.initials: C
authors.lastname: Yu
authors.forename: Hanguo
authors.initials: H
authors.lastname: Wang
authors.forename: Qing
authors.initials: Q
authors.lastname: Yu
mesh_terms: D000328:Adult; D001047:Apicoectomy / Q000379:methods*; D016866:Bacteroidaceae Infections / Q000628:therapy; D018441:Biofilms; D003475:Curettage; D003751:Dental Fistula / Q000382:microbiology / Q000601:surgery; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008855:Microscopy, Electron, Scanning; D010485:Periapical Periodontitis / Q000382:microbiology / Q000601:surgery*; D010486:Periapical Tissue / Q000382:microbiology / Q000601:surgery; D016966:Porphyromonas gingivalis / Q000302:isolation & purification / Q000502:physiology; D018720:Prevotella / Q000302:isolation & purification / Q000502:physiology; D012008:Recurrence; D019233:Retreatment; D012184:Retrograde Obturation; D013290:Streptococcal Infections / Q000628:therapy; D013298:Streptococcus sanguis / Q000302:isolation & purification / Q000502:physiology; D019227:Tooth Apex / Q000382:microbiology*