A study on the root canal morphology of primary molars by high-resolution computed tomography

Background/purpose: High-resolution computed tomography (mu CT) was used to construct three-dimensional (3D) morphology of root canal systems of primary molars. Materials and methods: Twenty-nine extracted primary molars, including eight maxillary first molars, 10 maxillary second molars, two mandibular first molars, and nine mandibular second molars, without obvious root resorption were used. A mu CT device was used to scan the teeth. Data were processed to reconstruct 3D images. Roots and root canal systems were analyzed from 3D images of the teeth and cross-sectional mu CT images at different root levels. Results: In primary molars, numbers of roots and root canals varied from two to three and three to four, respectively. Maxillary molars exhibited more one-canal than two-canal roots, yet there were equal numbers in mandibular molars. Fusion between the distobuccal and palatal roots in maxillary molar was common with a greater prevalence in maxillary first molars. More ovoid root canal outlines were found apically. Root canal outlines remained consistent from one level to the next in 76% of the roots. Conclusion: This study showed the complexity of root canal system in primary molars. Understanding variations in root canal systems would improve the interpretative capability for correct diagnoses. Copyright (C) 2013, Association for Dental Sciences of the Republic of China. Published by Elsevier Taiwan LLC. All rights reserved.