title: Apical Root Canal Morphology of Mesial Roots of Mandibular First Molar Teeth with Vertucci Type II Configuration by Means of Micro-Computed Tomography.
abstract: BACKGROUND
  The aim of this study was to assess the features of the apical root canal anatomy and its relation to the level at which 2 separate root canals merge in the mesial roots of the mandibular first molars with Vertucci type II canal configuration by using micro-computed tomography analysis.
  
  
  METHODS
  The anatomic features of the apical 3 mm of root canals in 83 mesial roots of mandibular first molar teeth were investigated by micro-computed tomography and software imaging according to the level at which 2 separate root canals merge. The most apical slice where a visible root canal was detectable was recorded as 0 level. The specimens from where 2 root canals rejoin at within 3 mm from the 0 level were then assigned to group 1 (n = 37), whereas the specimens from where root canals rejoin 3-9 mm from the 0 level were assigned to group 2 (n = 46). Data were presented by using descriptive statistics and Mann-Whitney U tests, with the significance level set at 5%.
  
  
  RESULTS
  In all specimens the long oval type of cross-sectional shape increased from 50.9% at 1 mm to 80.5% at 3 mm. Group 1 presented significantly higher major diameter values compared with group 2 (P < .05). There was no significant difference regarding minor diameter values (P > .05) between groups. Group 2 displayed significantly higher roundness values than group 1 (P < .05).
  
  
  CONCLUSIONS
  A long oval root cross section of apical root canal anatomy is more prevalent in roots for which 2 root canals merge within apical 3 mm of root canals.
authors.affiliation: Faculty of Dentistry, Department of Endodontics, Ondokuz Mayıs University, Samsun, Turkey.
authors.forename: Ali
authors.initials: A
authors.lastname: Keleş
authors.affiliation: Faculty of Dentistry, Department of Endodontics, Ondokuz Mayıs University, Samsun, Turkey. Electronic address: canglkarabulut@gmail.com.
authors.forename: Cangül
authors.initials: C
authors.lastname: Keskin
mesh_terms: D006801:Humans; D008334:Mandible; D008963:Molar / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D019227:Tooth Apex / Q000033:anatomy & histology; D014092:Tooth Root / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D055114:X-Ray Microtomography
keywords: Micro-computed tomography scanning; root canal anatomy; three-dimensional morphology