Root canal conicity determination of primary second molars using nanotomography: An in vitro study

BackgroundThe conicity of the root canals of primary teeth is an important measure for endodontic therapies. However, determining this conicity depends on the methods employed, which requires further investigation.AimThe aim of this study was to determine the conicity of the root canals of the upper and lower primary second molars using nanotomography (nCT).DesignAn in vitro study was performed using nine primary second molars, both upper and lower, subjected to nCT. Comparisons between the diameters of root canals were performed between the thirds (cervical—D0, middle—D5, and apical—D7). The conicity (%) was determined for each root canal from cervical to apical. Data were statistically analyzed with a significance level of 5%.ResultsThe conicity ranged from 2% to 8% for the upper primary second molars. Significant differences in root canal diameter between the thirds (D0, D5, and D7 points) were observed in the mesio‐ and distobuccal roots (p < .05), but not in the palatal roots (p > .05). For the lower primary second molars, the conicity ranged from 2% to 17%, as well as significant differences in root canal diameter between the thirds (D0, D5, and D7 points) were observed in all roots (distal, mesiobuccal, and mesiolingual; p < .05).ConclusionThe conicity of the upper primary second molars was different from that of the lower ones, which showed a greater variability.