title: Participation of bacterial biofilms in refractory and chronic periapical periodontitis.
abstract: The aim of this study was to examine morphologically the participation of extraradicular biofilm in refractory periapical periodontitis. Six teeth and five extruded root filling gutta-percha points associated with refractory periapical periodontitis were investigated by scanning electron microscope. In nine of 11 samples examined, bacterial biofilms were seen at the extraradicular area. The gutta-percha surface was covered with glycocalyx-like structures, and filaments, long rods, and spirochete-shaped bacteria were predominant in the extraradicular sites. Planktonic cells, which were filaments and spirochete-shaped bacteria, emigrated from the glycocalyx structures in some spots. In the extracted teeth, biofilm consisting of both bacteria and glycocalyx-like structures were observed on the periapical root surfaces. Next to the residual periodontal ligament, a few filaments, rods, and fusiforms were attached on the healthy cementum surface. The present findings suggested that bacterial biofilms formed in the extraradicular areas were related to refractory periapical periodontitis.
authors.affiliation: Department of Restorative Dentistry and Endodontology, Osaka University Graduate, School of Dentistry, Suita, Japan.
authors.forename: Yuichiro
authors.initials: Y
authors.lastname: Noiri
authors.forename: Atsushi
authors.initials: A
authors.lastname: Ehara
authors.forename: Takashi
authors.initials: T
authors.lastname: Kawahara
authors.forename: Naoki
authors.initials: N
authors.lastname: Takemura
authors.forename: Shigeyuki
authors.initials: S
authors.lastname: Ebisu
mesh_terms: D000293:Adolescent; D000328:Adult; D001419:Bacteria / Q000145:classification; D018441:Biofilms; D002908:Chronic Disease; D003739:Dental Cementum / Q000382:microbiology / Q000648:ultrastructure; D005260:Female; D019276:Glycocalyx / Q000382:microbiology / Q000648:ultrastructure; D006171:Gutta-Percha / Q000737:chemistry; D006801:Humans; D008297:Male; D008855:Microscopy, Electron, Scanning; D008875:Middle Aged; D010485:Periapical Periodontitis / Q000382:microbiology*; D010513:Periodontal Ligament / Q000382:microbiology / Q000648:ultrastructure; D012387:Root Canal Filling Materials / Q000737:chemistry; D013144:Spirochaetales / Q000254:growth & development; D013499:Surface Properties; D019227:Tooth Apex / Q000382:microbiology / Q000648:ultrastructure; D014092:Tooth Root / Q000382:microbiology / Q000648:ultrastructure
chemical_list: D012387:Root Canal Filling Materials; D006171:Gutta-Percha