title: Cone beam CT scans with and without artefact reduction in root fracture detection of endodontically treated teeth.
abstract: OBJECTIVE
  Cone beam CT (CBCT) is used widely to depict root fracture (RF) in endodontically treated teeth. Beam hardening and other artefacts due to gutta-percha may increase the time of the diagnosis and result in an incorrect diagnosis. Two CBCT machines, ProMax(®) (Planmeca, Helsinki, Finland) and Master 3D(®) (Vatech, Hwaseong, Republic of Korea), have the option of applying an artefact reduction (AR) algorithm. The aim of this study was to determine whether using an AR algorithm in two CBCT machines enhances the accuracy of detecting RFs in endodontically treated teeth.
  
  
  METHODS
  66 roots were collected and decoronated. All roots were treated endodontically using the same technique with gutta-percha and zinc oxide cement. One-half of the roots were randomly selected and fractured using a nail that was tapped gently with a hammer until complete fracture resulted in two root fragments; the two root fragments were glued together with one layer of methyl methacrylate. The roots were placed randomly in eight prepared beef rib fragments.
  
  
  RESULTS
  The highest accuracy was obtained when the ProMax was used without AR. The lowest accuracy was obtained with the Master 3D when used with AR. For both machines, accuracy was significantly higher without AR than with AR. Both with and without AR, the ProMax machine was significantly more accurate than the Master 3D machine. The same rank ordering was obtained for both sensitivity and specificity.
  
  
  CONCLUSIONS
  For both machines, AR decreased the accuracy of RF detection in endodontically treated teeth. The highest accuracy was obtained when using the ProMax without AR.
authors.affiliation: Department of Comprehensive Dentistry, University of Texas Health Science Center, San Antonio, TX 78229-3900, USA. boulosbchara@hotmail.com
authors.forename: B
authors.initials: B
authors.lastname: Bechara
authors.forename: C
authors.initials: C
authors.lastname: Alex McMahan
authors.forename: W S
authors.initials: WS
authors.lastname: Moore
authors.forename: M
authors.initials: M
authors.lastname: Noujeim
authors.forename: F B
authors.initials: FB
authors.lastname: Teixeira
authors.forename: H
authors.initials: H
authors.lastname: Geha
mesh_terms: D000465:Algorithms; D016477:Artifacts; D054893:Cone-Beam Computed Tomography / Q000379:methods*; D006171:Gutta-Percha; D006801:Humans; D018709:Statistics, Nonparametric; D014082:Tooth Fractures / Q000000981:diagnostic imaging*; D014092:Tooth Root / Q000000981:diagnostic imaging* / Q000473:pathology*; D019553:Tooth, Nonvital / Q000000981:diagnostic imaging*
chemical_list: D006171:Gutta-Percha