title: Location and negotiability of second mesiobuccal canal in upper molar by tomographic and anatomical macroscopic analysis.
abstract: OBJECTIVE
  The aim of this study was to assess the presence and negotiability of second mesiobuccal (MB2) canal at pulp chamber, cervical, medium and apical levels comparing the findings obtained by anatomical evaluation with cone-beam computed tomography (CBCT) images.
  
  
  METHODS
  56 and 43 human maxillary first and second upper molars, respectively, were assessed. The specimens were placed on an acrylic platform in a stationary position to identify the presence of MB2 canal at the pulp chamber floor, cervical, medium, and apical level. The samples were analyzed using two image acquisition softwares (XoranCat and DentalSlice) and subsequently by macroscopic anatomical analysis with a 4× magnifying glass. All data were summarized, and mean values, frequencies, and percentage values were calculated for each group of specimens.
  
  
  RESULTS
  DentalSlice and XoranCat images of first molars showed a rate concordance index (CI) of present MB2 canals in comparison to anatomic evaluations of 65.2 and 70.1%, respectively. On the second molars, the rate of CI reached about 80 % in both sets of images. In the first molars, 29.9% of canals localized by XoranCat images did not display anatomical negotiability; 34.8% of canals localized by DentalSlice images did not display anatomical negotiability. Among second molars, 18.6% of canals localized by XoranCat did not display anatomical negotiability; 19.8% of canals localized by DentalSlice did not display anatomical negotiability. On the first molars with anatomical negotiability, errors not identified by XoranCat and DentalSlice reached rates of 22.3 and 25.4%, respectively. Among second molars, error rates were 8.7% (XoranCat) and 11.6% (DentalSlice).
  
  
  CONCLUSIONS
  Our study indicated that (1) the tomographic image is an auxiliary way to detection and mapping of the MB2 canal in maxillary molars, (2) the tomographic image is ineffective in determining negotiability. Both image software packages used in this study showed similar results.
authors.affiliation: Department of Semiology and Clinics, School of Dentistry, Federal University of Pelotas, Gonçalves Chaves st. 457-Centro, Pelotas, RS, CEP 96015-560, Brazil.
authors.forename: Luiz Fernando Machado
authors.initials: LF
authors.lastname: Silveira
authors.forename: Mariana Marroni
authors.initials: MM
authors.lastname: Marques
authors.forename: Roberta Katrein
authors.initials: RK
authors.lastname: da Costa
authors.forename: Josué
authors.initials: J
authors.lastname: Martos
authors.forename: Alesandro
authors.initials: A
authors.lastname: Lorenzi
mesh_terms: D054893:Cone-Beam Computed Tomography; D006801:Humans; D008963:Molar / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D012016:Reference Values