A Micro-Computed Tomographic Evaluation of Root Canal Morphology of Mandibular First Molars in a Black South African Subpopulation.

: This study evaluates the root canal anatomy (main and accessory canals) of mandibular first molars in Black South Africans using micro-computed tomography. The effect of sex, arch side, and age are also investigated. : The number of root canals in each tooth and individual roots (including an observation of the middle-mesial and middle-distal canals), the number of accessory canals, accessory canal type, root canal thirds, and the prevalence of apical deltas were recorded. A chi-squared test of association ( < 0.05) was used to report on variables (sex, arch sides, and age). : In most teeth, either three (55.81%) or four canalled (24.42%) configurations were present. The middle-mesial canal was found in 18.6% of teeth (males and females), with a higher prevalence among females (23.68%). The middle-distal canal was found in 3.49% of teeth. Chamber canals were identified in 4.7% of teeth. Accessory canals most likely located in the apical third were found in approximately 84.9% and 86.1% of mesial roots and distal roots, respectively. Apical deltas were identified in 15.12% of mesial and 20.93% of distal roots. : Root canal anatomy in this population is diverse and includes differences in arch sides between the sexes.