Abstract : The purpose of this study was to investigate the root canal morphology of extracted two-rooted second mandibular molars.
Seventy-seven two-rooted mandibular second molars were used. Gutta-percha point was inserted into the root canal after root canal preparation by a standardized method. Transparent specimens were made from the test teeth and the root canal morphology was evaluated on images taken with a digital microscope.
As for the mesial root, 70.1% were two-root canals, whereas for the distal root 88.3% were single-root canals. Although two-rooted mandibular second molars have a simple root canal configuration, in some cases the root canal system is complex, so careful root canal detection is necessary.
Abstract : Purpose : Our aim was to assess the root and root canal morphology of mandibular second molars in a Japanese population using dental cone-beam computed tomography (CBCT). Materials and Methods : We analyzed CBCT images of 286 mandibular second molars of 145 patients. The following parameters were observed on CBCT : (1) number of roots and root canals ; (2) the classification of root canal configuration according to the method of Vertucci ; (3) bilateral occurrence of C-shaped roots ; (4) frequency of C-shaped roots by tooth position ; and (5) the classification of cross-sectional canal images of C-shaped canals. Results and Conclusion : Most of the mandibular second molars had two roots with three root canals (30.8%) or two root canals (24.5%), and most of the mesial root canals (43.0%) of the two rooted molars were type I. The prevalence of C-shaped roots was 39.9%, with a bilateral incidence of 35.5%. There was no difference in the frequency of C-shaped roots between the right- and left-side occurrences. The prevalence did not differ with tooth position. Most canals with continuous C-shapes appeared to fuse into one or divide into two canals toward the canal terminus. This study provided detailed information about the root and root canal morphology of mandibular second molars in a Japanese population.