Canal transportation and centering ratio after preparation of curved canals: A comparative evaluation of cone-beam computed tomography and micro-computed tomography

Objectives: This study aimed to compare cone-beam computed tomography (CBCT) and micro-computed tomography (micro-CT) for evaluation of canal transportation and centering ratio after instrumentation of curved canals. Materials: and Methods: A total of 20 mesiobuccal canals of mandibular molars were prepared by sequential rotary system. All specimens underwent CBCT and micro-CT before and after instrumentation and the magnitude of transportation and centering ratio were measured. The accuracy and the agreement between the two modalities were calculated considering the acceptable transportation of ≤ 0.15 mm. The agreement between the modalities was also assessed by calculating the intraclass correlation coefficient (ICC). Results: : Transportation was detected by both modalities at all distances from the apex after instrumentation. Agreement between the two modalities in assessment of canal transportation was observed in 16 specimens at 1 mm, 17 specimens at 3 mm, and 15 specimens at 5 and 7 mm from the apex, out of 20 specimens, yielding 80%, 85%, 75% and 75% accuracy, respectively. ICC for transportation and centering ratio was much lower than 0.75 indicating poor agreement between the modalities. Conclusions: : CBCT and micro-CT do not have a good agreement in assessing transportation and centering ratio. Micro-CT is still recommended for evaluating transportation in vitro, due to higher resolution and better visualization of details. Clinical relevance: CBCT is recommended for assessment of canal transportation in the clinical setting; however, it cannot replace micro-CT for in vitro studies, and micro-CT remains the modality of choice for in vitro assessments.