title: Root canal morphology of primary molars: a micro-computed tomography study.
abstract: OBJECTIVE
  This was to investigate the root canal morphology of primary molar teeth using micro-computed tomography.
  
  
  METHODS
  Primary maxillary (n = 20) and mandibular (n = 20) molars were scanned at a resolution of 16.7 μm and analysed regarding the number, location, volume, area, structured model index (SMI), area, roundness, diameters, and length of canals, as well as the thickness of dentine in the apical third. Data were statistically compared by using paired-sample t test, independent sample t test, and one-way analysis of variance with significance level set as 5%.
  
  
  RESULTS
  Overall, no statistical differences were found between the canals with respect to length, SMI, dentine thickness, area, roundness, and diameter (p > 0.05). A double canal system was observed in the mesial and mesio-buccal roots of the mandibular and maxillary molars, respectively. The thickness in the internal aspect of the roots was lower than in the external aspect. Cross-sectional evaluation of the roots in the apical third showed flat-shaped canals in the mandibular molars and ribbon- and oval-shaped canals in the maxillary molars.
  
  
  CONCLUSIONS
  External and internal anatomy of the primary first molars closely resemble the primary second molars. The reported data may help clinicians to obtain a thorough understanding of the morphological variations of root canals in primary molars to overcome problems related to shaping and cleaning procedures, allowing appropriate management strategies for root canal treatment.
authors.affiliation: Department of Pediatric Dentistry, Dental School of Ribeirão Preto, University of São Paulo, Av. do Café s/no, Bairro Monte Alegre, São Paulo, Ribeirão Preto, CEP 14049-904, Brazil.
authors.forename: A C
authors.initials: AC
authors.lastname: Fumes
authors.forename: M D
authors.initials: MD
authors.lastname: Sousa-Neto
authors.forename: G B
authors.initials: GB
authors.lastname: Leoni
authors.forename: M A
authors.initials: MA
authors.lastname: Versiani
authors.forename: L A B
authors.initials: LA
authors.lastname: da Silva
authors.forename: R A B
authors.initials: RA
authors.lastname: da Silva
authors.forename: A
authors.initials: A
authors.lastname: Consolaro
mesh_terms: D019412:Anatomy, Cross-Sectional / Q000379:methods; D003786:Dental Pulp Cavity / Q000000981:diagnostic imaging*; D003804:Dentin / Q000000981:diagnostic imaging; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000379:methods; D008334:Mandible / Q000000981:diagnostic imaging; D008437:Maxilla / Q000000981:diagnostic imaging; D008963:Molar / Q000000981:diagnostic imaging*; D019227:Tooth Apex / Q000000981:diagnostic imaging; D014092:Tooth Root / Q000000981:diagnostic imaging; D014094:Tooth, Deciduous / Q000000981:diagnostic imaging*; D055114:X-Ray Microtomography / Q000379:methods*