title: C-shaped canal system in mandibular second molars Part III: The morphology of the pulp chamber floor.
abstract: The purpose of this study was to investigate the morphology of pulp chamber floors in mandibular second molars with a C-shaped canal system. Forty-four extracted mandibular second molars with C-shaped roots were collected from a native Chinese population. After the teeth were scanned by the micro-computed tomography (microCT), the pulp chamber floors were reconstructed three-dimensionally using three-dimensional software. The reconstructed images were classified into four types based on the shape of the pulp chamber floor and the location of the dentin fusion between the peninsular-like floor and the pulp chamber wall. Of the 44 reconstructed pulpal floors, 38 (86.37%) were C-shaped (peninsula-like floor) in which 8 (18.18%) had a continuous C-shaped orifice (type I); 16 (36.37%) had a dentin fusion between the peninsula-like floor and buccal pulp chamber wall, forming one or two mesial orifice(s) and a distal orifice (type II); and 14 (31.82%) had a dentin fusion between the peninsula-like floor and the mesial pulp chamber wall, forming a large mesiobuccal-distal (MB-D) orifice and a small mesiolingual orifice (type III). Six (13.63%) teeth did not have a C-shaped floor configuration (type IV). The number and configuration of the canals at different levels below the orifices were analyzed. The results suggested that most teeth in this study with C-shaped roots also have a C-shaped pulpal floor and that a new classification of pulpal floor anatomy would be helpful in locating the C-shaped canals.
authors.affiliation: Endodontic Center, School & Hospital of Stomatology, Wuhan University, Wuhan, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Min
authors.forename: Bing
authors.initials: B
authors.lastname: Fan
authors.forename: Gary S P
authors.initials: GS
authors.lastname: Cheung
authors.forename: James L
authors.initials: JL
authors.lastname: Gutmann
authors.forename: Mingwen
authors.initials: M
authors.lastname: Fan
mesh_terms: D019412:Anatomy, Cross-Sectional; D044466:Asian People; D002681:China; D002965:Classification; D003196:Computer Graphics; D003786:Dental Pulp Cavity / Q000033:anatomy & histology*; D003804:Dentin; D006801:Humans; D021621:Imaging, Three-Dimensional; D008334:Mandible; D008963:Molar / Q000033:anatomy & histology*; D009811:Odontometry; D014057:Tomography, X-Ray Computed / Q000379:methods; D014092:Tooth Root / Q000033:anatomy & histology*