title: The anatomy of the root canal system of three-rooted maxillary premolars analysed using high-resolution computed tomography.
abstract: OBJECTIVE
  To analyse the anatomy of the root canal system of maxillary premolars with three distinct roots using high-resolution computed tomography (μCT).
  
  
  METHODS
  Ten three-rooted human maxillary premolars were scanned transversally from crown to apex at 42μm intervals using a high-resolution desktop μTC system (Skyscan 1072). The images were processed and analysed for the following features: cross section of the roots and canals in the apical, middle and coronal thirds; location of the apical foramen; distance from the pulp chamber roof to the bifurcation and trifurcation of the canals and anatomic variations of the root canal system. The results were expressed descriptively.
  
  
  RESULTS
  The cross-sectional shape of canals was heterogeneous along the length of the roots. The location of the apical foramen varied, tending to lie palatally or distally. The buccal pulp horn was larger than the palatal. The mean distance from the most cervical region of the pulp chamber roof to the bifurcation and trifurcation of the canals was 3.13 and 5.08mm, respectively.
  
  
  CONCLUSIONS
  Features of the internal anatomy of the pulp cavity of three-rooted maxillary premolars were identified with the use of μCT. The results revealed the heterogeneity of three-rooted maxillary premolars.
authors.affiliation: Post-Graduate Program in Dentistry, Pontifical Catholic University of Rio Grande do Sul - PUCRS, Porto Alegre, Brazil. endopelisser@gmail.com
authors.forename: F V
authors.initials: FV
authors.lastname: Vier-Pelisser
authors.forename: P M H
authors.initials: PM
authors.lastname: Dummer
authors.forename: S
authors.initials: S
authors.lastname: Bryant
authors.forename: C
authors.initials: C
authors.lastname: Marca
authors.forename: M V R
authors.initials: MV
authors.lastname: Só
authors.forename: J A P
authors.initials: JA
authors.lastname: Figueiredo
mesh_terms: D019412:Anatomy, Cross-Sectional; D001641:Bicuspid / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D003786:Dental Pulp Cavity / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D006801:Humans; D008437:Maxilla; D014057:Tomography, X-Ray Computed / Q000379:methods