title: Influence of scan mode (180°/360°) of the cone beam computed tomography for preoperative dental implant measurements.
abstract: OBJECTIVE
  The aim of this study was to evaluate the effect of scan mode of the cone beam computed tomography (CBCT) in the preoperative dental implant measurements.
  
  
  METHODS
  Completely edentulous mandibles with entirely resorbed alveolar processes were selected for this study. Five regions were selected (incisor, canine, premolar, first molar, and second molar). The mandibles were scanned with Next Generation i-CAT CBCT unit (Imaging Sciences International, Inc, Hatfield, PA, USA) with half (180°) and full (360°) mode. Two oral radiologists performed vertical measurements in all selected regions; the measurements of half of the sample were repeated within an interval of 30 days. The mandibles were sectioned using an electrical saw in all evaluated regions to obtain the gold standard. The intraclass correlation coefficient was calculated for the intra- and interobserver agreement. Descriptive statistics were calculated as mean, median, and standard deviation. Wilcoxon signed rank test was used to determine the correlation between the measurements obtained in different scan mode with the gold standard. The significance level was 5%.
  
  
  RESULTS
  The values of intra- and interobserver reproducibility indicated a strong agreement. In the dental implant measurements, except the bone height of the second molar region in full scan mode (P = 0.02), the Wilcoxon signed rank test did not show statistical significant difference with the gold standard (P > 0.05).
  
  
  CONCLUSIONS
  Both modes provided real measures, necessary when performing implant planning; however, half scan mode uses smaller doses, following the principle of effectiveness. We believe that this method should be used because of the best dose-effect relationship and offer less risk to the patient.
authors.affiliation: Division of Oral Radiology, Department of Oral Diagnosis, Piracicaba Dental School, State University of Campinas, Piracicaba, São Paulo, Brazil.
authors.forename: Frederico S
authors.initials: FS
authors.lastname: Neves
authors.forename: Taruska V
authors.initials: TV
authors.lastname: Vasconcelos
authors.forename: Paulo S F
authors.initials: PS
authors.lastname: Campos
authors.forename: Francisco
authors.initials: F
authors.lastname: Haiter-Neto
authors.forename: Deborah Q
authors.initials: DQ
authors.lastname: Freitas
mesh_terms: D016301:Alveolar Bone Loss / Q000000981:diagnostic imaging*; D054893:Cone-Beam Computed Tomography; D003758:Dental Implantation, Endosseous; D015921:Dental Implants; D006801:Humans; D066298:In Vitro Techniques; D007575:Jaw, Edentulous / Q000000981:diagnostic imaging* / Q000601:surgery; D008334:Mandible / Q000000981:diagnostic imaging* / Q000601:surgery; D015203:Reproducibility of Results
chemical_list: D015921:Dental Implants