title: MicroCT analysis of a retrieved root restored with a bonded fiber-reinforced composite dowel: a pilot study.
abstract: OBJECTIVE
  This evaluation aimed to (1) validate micro-computed tomography (microCT) findings using scanning electron microscopy (SEM) imaging, and (2) quantify the volume of voids and the bonded surface area resulting from fiber-reinforced composite (FRC) dowel cementation technique using microCT scanning technology/3D reconstructing software.
  
  
  METHODS
  A fiberglass dowel was cemented in a condemned maxillary lateral incisor prior to its extraction. A microCT scan was performed of the extracted tooth creating a large volume of data in DICOM format. This set of images was imported to image-processing software to inspect the internal architecture of structures.
  
  
  RESULTS
  The outer surface and the spatial relationship of dentin, FRC dowel, cement layer, and voids were reconstructed. Three-dimensional spatial architecture of structures and volumetric analysis revealed that 9.89% of the resin cement was composed of voids and that the bonded area between root dentin and cement was 60.63% larger than that between cement and FRC dowel.
  
  
  CONCLUSIONS
  SEM imaging demonstrated the presence of voids similarly observed using microCT technology (aim 1). MicroCT technology was able to nondestructively measure the volume of voids within the cement layer and the bonded surface area at the root/cement/FRC interfaces (aim 2).
  
  
  CONCLUSIONS
  The interfaces at the root dentin/cement/dowel represent a timely and relevant topic where several efforts have been conducted in the past few years to understand their inherent features. MicroCT technology combined with 3D reconstruction allows for not only inspecting the internal arrangement rendered by fiberglass adhesively bonded to root dentin, but also estimating the volume of voids and contacted bond area between the dentin and cement layer.
authors.affiliation: Department of Prosthodontics, Bauru School of Dentistry, Brazil. fcesarlorenzoni@yahoo.com.br
authors.forename: Fabio Cesar
authors.initials: FC
authors.lastname: Lorenzoni
authors.forename: Estevam A
authors.initials: EA
authors.lastname: Bonfante
authors.forename: Gerson
authors.initials: G
authors.lastname: Bonfante
authors.forename: Leandro M
authors.initials: LM
authors.lastname: Martins
authors.forename: Lukasz
authors.initials: L
authors.lastname: Witek
authors.forename: Nelson R F A
authors.initials: NR
authors.lastname: Silva
mesh_terms: D002484:Cementation / Q000379:methods; D003188:Composite Resins / Q000737:chemistry*; D001840:Dental Bonding; D003764:Dental Materials / Q000737:chemistry*; D003786:Dental Pulp Cavity / Q000000981:diagnostic imaging / Q000648:ultrastructure; D003804:Dentin / Q000000981:diagnostic imaging / Q000648:ultrastructure; D005898:Glass / Q000737:chemistry*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000379:methods; D007180:Incisor / Q000000981:diagnostic imaging / Q000648:ultrastructure; D008855:Microscopy, Electron, Scanning; D010865:Pilot Projects; D011176:Post and Core Technique / Q000295:instrumentation*; D019279:Resin Cements / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry; D013499:Surface Properties; D014092:Tooth Root / Q000000981:diagnostic imaging / Q000648:ultrastructure; D055114:X-Ray Microtomography / Q000379:methods; D015040:Zirconium / Q000737:chemistry
chemical_list: D003188:Composite Resins; D003764:Dental Materials; D019279:Resin Cements; C083568:Z100 composite resin; C009753:fiberglass; D012822:Silicon Dioxide; D015040:Zirconium
keywords: Fiber-resin reinforced dowel; SEM; dowel cementation; microCT