Abstract
Background: The success of endodontic treatment depends on detection of all root canals so that they could be cleaned, shaped and
obturated appropriately. To achieve this, it is essential to know root canals complexities such as the number of canals and types of each
root canal, which are genetically determined. Besides, the highest failure rates occur in maxillary first molars.
Objectives: Therefore, the aim of this study was to investigate the root and canal morphology of maxillary first molars in an Iranian
population using cone-beam computed tomography (CBCT).
Materials and Methods: In this study, images of 156 extracted maxillary first molars placed in the waxed blocks were produced using
CBCT. Two professional investigators checked images by NNT software in New Tom 3G system. Axial view and cross section of 1 mm
thickness were used. The number of roots, canals, each roots canal, MB1
-MB2 orifice distances and canal types of the Vertucci classification
were recorded. Finally, data was analyzed using SPSS16 software.
Results: We found 100% of cases with three separated roots, from which 69.23% had four canals including MB2 and 30.77% with three canals.
71.3% of mesiobuccal roots were two canals of type two Vertucci and 28.7% type 4 with the mean distance value of 2.55 ± 0.57 mm between
MB1
and MB2 orifice.
Conclusions: Most extracted maxillary first molars were three rooted and four canals. CBCT has relatively high reproducibility and
accuracy of distinguishing MB2 canal.