Methods: A total of 155 mandibular first permanent molars extracted from indigenous Kenyans in Nairobi University Dental Clinic were evaluated.
Access cavities were prepared and pulp tissue removed using 5.25% Sodium hypochlorite solution. The teeth in groups of twelve were then embedded in a clear plastic box up to cemento-enamel junction and placed in the patient compartment of CBCT for scanning. Slice thickness was set at 0.12mm. The acquired data was analyzed using Xoran software (version 3.1.5.9) and SPSS (version 12.0).
Observations were made on the number of canals per root, canal configuration using Vertuccis (1984) classification, lateral canals, inter-canal communications as well as number and position of apical foramen
Results: Most of the molars had two roots (99.4%), only one(0.6%) possessed a third root (distolingual root). Fusion of roots occurred in 5.8% of the sample. Only one tooth presented with C-shaped roots.
Majority of the distal roots (74.2%) had type I (single canals). Mesial roots demonstrated a wide range of canal configuration with the commonest being type IV (50.3%) and type II (35.5%); in addition, there were seven other canal types (non-Vertuccis).
Lateral canals were more in mesial roots (11%) compared to distal roots(5.8%).Majority of the roots contained one or two apical foramen (98%) and apical third had the highest prevalence of lateral canals (89% for mesial and 94.2% for distal)
Conclusion: CBCT permits a non-invasive diagnostic approach to identify the patterns, size and anastomoses of the canals. Morphology of teeth in this Kenyan population showed variation from those in other studies on different populations in number of third roots, C-shaped roots, root fusion and canal patterns which could be attributed to racial differences.