title: Study of root canal accessibility in human primary molars.
abstract: The aim of the present study was to provide a general scheme for pulpectomy of primary molars that may be useful for decision-making about negotiation of root canals and selection of appropriate instruments. A total of 160 vital primary molars in 85 patients (40 males, 45 females) aged 4-6 years were selected. After taking primary radiographs, local anesthesia was induced, and the teeth were isolated using a rubber dam. Canal accessibility index (CAI) and tooth accessibility index (TAI) were calculated according to initial file size. Mandibular first molars had either three canals (79.2%) or four canals (20.8%), and all second molars had four canals. Maxillary first molars had three canals and second molars had either three canals (70.9%) or four canals (29.1%). Lower accessibility of the mandibular first molar distobuccal root accounted for the lower accessibility of these teeth in comparison with mandibular second molars. While three-canal maxillary second molars were more accessible due to the lower accessibility of the distobuccal canal of the maxillary first molar, poor accessibility of the distal canal in four-canal second molars was responsible for the difficult accessibility of these teeth. In conclusion, it seems that the accessibility of a single canal in each tooth determines the difficulty of accessibility for any given tooth. Moreover, while primary second molars are more accessible than first molars, all of them are negotiable.
authors.affiliation: Department of Pediatric Dentistry, Tabriz University of Medical Sciences, Tabriz, Iran.
authors.forename: Naser A
authors.initials: NA
authors.lastname: Aminabadi
authors.forename: Ramin M Z
authors.initials: RM
authors.lastname: Farahani
authors.forename: Esrafil B
authors.initials: EB
authors.lastname: Gajan
mesh_terms: D000779:Anesthetics, Local / Q000008:administration & dosage; D002648:Child; D002675:Child, Preschool; D003442:Crowns; D003657:Decision Making; D003731:Dental Caries / Q000628:therapy; D003786:Dental Pulp Cavity / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D005240:Feasibility Studies; D005260:Female; D005544:Forecasting; D005899:Glass Ionomer Cements; D006801:Humans; D008012:Lidocaine / Q000008:administration & dosage; D008297:Male; D008334:Mandible; D008437:Maxilla; D008963:Molar / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D009407:Nerve Block / Q000379:methods; D011670:Pulpectomy / Q000295:instrumentation / Q000379:methods*; D011859:Radiography; D012387:Root Canal Filling Materials / Q000627:therapeutic use; D018915:Root Canal Preparation / Q000295:instrumentation / Q000379:methods; D016733:Rubber Dams; D014094:Tooth, Deciduous / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D015035:Zinc Oxide-Eugenol Cement / Q000627:therapeutic use
chemical_list: D000779:Anesthetics, Local; D005899:Glass Ionomer Cements; D012387:Root Canal Filling Materials; D015035:Zinc Oxide-Eugenol Cement; D008012:Lidocaine