title: Accuracy of Digital Subtraction Radiography in the Detection of Vertical Root Fractures.
abstract: BACKGROUND
  The objective of this study was to evaluate the accuracy of digital subtraction radiography in the diagnosis of vertical root fractures (VRFs).
  
  
  METHODS
  Twenty decoronated uniradicular human teeth were placed in the alveoli of a dry mandible and radiographed twice, first without (unfilled roots) and then with (filled roots) a gutta-percha cone placed into the root canal. Roots were then removed from the dry mandible, and vertical fractures were created with the aid of a universal testing machine. The fractured roots were repositioned in the mandibular alveoli and again radiographed twice. Radiographic images were subtracted by using the Regeemy software in 3 test situations: group 1, initial radiographic images of unfilled roots and images of fractured or non-fractured unfilled roots; group 2, initial radiographic images of unfilled roots and images of fractured or non-fractured filled roots; and group 3, initial radiographic images of filled roots and images of fractured or non-fractured filled roots. Three examiners evaluated all the original digital radiographs, as well as the subtracted images, for the presence or absence of VRFs. Numerical data were subject to statistical analysis with the use of receiver operator characteristic (ROC) curves.
  
  
  RESULTS
  The areas under the ROC curve for groups 1, 2, and 3 were 0.86, 0.73, and 0.66, respectively. For the original digital radiographs, areas under the ROC curve were 0.80 (without gutta-percha) and 0.73 (with gutta-percha). No statistically significant differences were found between subtracted and original images.
  
  
  CONCLUSIONS
  Digital subtraction radiography could be considered as an alternative tool for the investigation of VRFs because of its comparable diagnostic accuracy to existing methods.
authors.affiliation: Division of Oral Radiology, Department of Oral Diagnosis, Piracicaba Dental School, State University of Campinas, São Paulo, Brazil.
authors.forename: Polyane Mazucatto
authors.initials: PM
authors.lastname: Queiroz
authors.affiliation: Division of Oral Radiology, Department of Oral Diagnosis, Piracicaba Dental School, State University of Campinas, São Paulo, Brazil. Electronic address: helenaarn_@hotmail.com.
authors.forename: Helena Aguiar Ribeiro
authors.initials: HA
authors.lastname: Nascimento
authors.affiliation: Division of Oral Radiology, Department of Oral Diagnosis, Piracicaba Dental School, State University of Campinas, São Paulo, Brazil.
authors.forename: Thais Diniz Jacome
authors.initials: TD
authors.lastname: da Paz
authors.affiliation: Division of Oral Radiology, Department of Oral Diagnosis, Piracicaba Dental School, State University of Campinas, São Paulo, Brazil.
authors.forename: Felipe Nogueira
authors.initials: FN
authors.lastname: Anacleto
authors.affiliation: Division of Oral Radiology, Department of Oral Diagnosis, Piracicaba Dental School, State University of Campinas, São Paulo, Brazil.
authors.forename: Deborah Queiroz
authors.initials: DQ
authors.lastname: Freitas
mesh_terms: D006171:Gutta-Percha; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008334:Mandible / Q000000981:diagnostic imaging; D011176:Post and Core Technique; D012372:ROC Curve; D019252:Radiography, Dental, Digital / Q000379:methods*; D012387:Root Canal Filling Materials; D012389:Root Canal Obturation; D012390:Root Canal Therapy; D012680:Sensitivity and Specificity; D014082:Tooth Fractures / Q000000981:diagnostic imaging*; D014092:Tooth Root / Q000000981:diagnostic imaging* / Q000293:injuries*
chemical_list: D012387:Root Canal Filling Materials; D006171:Gutta-Percha
keywords: Digital subtraction radiography (DSR); radiography; vertical root fracture