Root and canal morphology of maxillary premolar teeth in an Egyptian subpopulation using two classification systems: a cone beam computed tomography study

Aim To investigate the number of roots and root canal configurations using two coding systems and the root canal diverging and merging levels in extracted maxillary premolars in an Egyptian subpopulation using cone beam computed tomography (CBCT). Methodology A total of 700 maxillary premolars were examined using CBCT in an Egyptian subpopulation. The number of roots was identified, and root canal configurations were classified according to Vertucci's classification and a new system for classifying root and canal morphology. In addition, the position where roots bifurcated and the levels where canals merged or diverged were identified. Fisher's exact test and independent t-test were used for statistical analysis, and the level of significance was set at 0.05 (P = 0.05). Results More than half of maxillary first premolars were double-rooted, and the majority of maxillary second premolars were single-rooted (P < 0.001). Most of the double-rooted samples had bifurcations in the middle of the root. According to the Vertucci classification, canal configuration type IV was the most common in both first and second maxillary premolars. According to the new system, the code (FP)-F-2 B-1 P-1 was the most common for maxillary first premolars, whilst (SP)-S-2 B-1 P-1, (SP2)-S-1 and (SP2-1)-S-1 codes were the most common for maxillary second premolars. The three-canalled morphology in double-and three-rooted maxillary premolars had considerable variations. Root canal merging and diverging levels were comparable in both tooth types. Conclusion Maxillary premolars in this Egyptian subpopulation had a wide range of root and canal anatomical variations. Clinicians should be aware of where canals merge and diverge to facilitate the treatment of all canals. The new system for classifying canal morphology describes the root and canal configurations in a more accurate and practical manner compared to the Vertucci classification.