A cone-beam computer tomographic study of root and canal morphology of mandibular first and second premolars

The success of endodontic treatment depends on a knowledge of the root canal system. The purpose of this study was to investigate the root and canal morphology of mandibular first and second premolars in a group of patients in RSU Library. Digital CBCT images of the mandibular first and second premolars were collected from patients who had undergone CBCT scanning for diagnostic purposes at RSU Library from November 2017 to September 2020. Subjects under 16 and over 60 years of age and those with any evidence of endodontic treatment, internal or external resorptions were excluded. The final study enrolled 70 patients. Anatomy of 105 teeth were analysed. The number of roots and canal morphology were tabulated according Vertucci classification. All CBCT images were evaluated by a single dentist. For the mandibular first premolars, the most common Vertucci classification were type I (1, 34,5%), type V (1-2, 31%) and type III (1-2-1, 25,9%), and least common was type VII (1-2-1-2, 1,7%). Unreadable apical anatomy was presented in 6,9% cases. Three roots were found in 1,8% of teeth. For mandibular second premolars, the most frequent Vertucci classification was type I (1, 85,1%), least common were type V (1-2, 10,6%) and type III (1-2-1, 4,3%). First mandibular premolar shows various root configurations. There is high incidence of one rooted tooth with most frequent Vertucci classification type I, II and III, followed by incidence of two roots. Three roots are rarely found. All the second mandibular premolars show one root appearance, with most frequent Vertucci classification type I.