Identification of root canals in molars by dental computed tomography

Objectives: To compare the three-dimensional, dental application, cone beam computed tomography (CT) system of imaging to diafanization technique for their ability to identify root canals in extracted human molars. Methods: Twenty mandibular human molars were distributed randomly into two groups of 10 teeth each. Group I, standard access was made in each tooth until the pulp chamber. The teeth were stored in 5% NaOCl for 4 days and the solution was changed every 24 h to remove pulp tissue. The teeth were then washed in tap water for 6 h. These teeth were decalcified in 5% hydrochloric acid which was changed every 24 h until all had been completed dissolved. After decalcification, the teeth were washed in tap water for 24 h and dehydrated in alcohol (80-100%). Gelatin with India ink was then injected into the root canals. The teeth were cleared in methylsalicylate. Group II, teeth were then imaged and with the 3D Accuitomo, dental computed tomograph. The source images were registered and CT slices were generated using 3D Tomo X Software. One observer was asked to identify the number of canals in the diafanization group and the CT image group using specific criteria. Ground truth was established by cross-sectioning the teeth at the coronal, middle, and apical thirds of the roots and directly visualizing the root canal morphology. Results: Both, CT imaging and diafanization technique, detected 100% of third canals in mandibular molars. The differences in canal detection between the two techniques were statistically similar (p>0.05). Conclusions: In this study, the dental computed tomography system of digital imaging was similar to diafanization technique in the detection of root canals in mandibular human molars, however the CT system may be useful for the detection of root canals with no-destruction of the regular dental structures in experimental endodontology.