Root and canal morphology of mandibular first and second permanent molar teeth in a Ugandan population

We investigated root and canal morphology of permanent mandibular molar teeth in a Ugandan population. Mandibular first (n = 224) and second (n = 223) molars were collected from patients visiting dental clinics in Kampala and prepared by a clearing technique. An endodontic access cavity was prepared in each tooth. The teeth were consecutively immersed in 5% sodium hypochlorite, 10% nitric acid, and 99% methyl salicylate. India ink was coronally injected into the pulp chamber and withdrawn apically by suction. The teeth were viewed under a magnifying lens and the numbers of root canals and their configurations, lateral canals, intercanal communications, and multiple apical foramina were recorded, along with the number of roots and their morphology. Student's t test for independent samples was used to assess significant differences in the root canal system. All specimens were two-rooted with one mesial and one distal root. Root fusion was more frequent in the second than in the first molar: 3.2% versus 0.4%. Vertucci type IV canal configuration was most frequently recorded in the mesial root of the first (44.6%) and second (49.8%) molars. Type 1 canal configuration was predominant in the distal root in first (84.8%) and second (94.2%) molars. Multiple apical foramina were more frequent in the first than in the second molar, as were intercanal communications and lateral canals. Type I and IV canal configurations were predominant in the distal and mesial roots, respectively, of both the first and second molars.