Elen de Souza Tolentino1, Pablo Andrés Amoroso-Silva2, Murilo Priori Alcalde3, Heitor Marques Honório4, Lilian Cristina Vessoni Iwaki5, Izabel Regina Fischer Rubira-Bullen6, Marco Antônio Húngaro-Duarte3. 1. Department of Dentistry, State University of Maringá, Maringá, PR, Brazil. Electronic address: elen_tolentino@hotmail.com. 2. Department of Restorative Dentistry, State University of Londrina, Londrina, PR, Brazil. 3. Departments of Operative Dentistry, Endodontics, and Dental Materials, Bauru School of Dentistry, University of São Paulo, Bauru, São Paulo, Brazil. 4. Department of Pediatrics Dentistry, Orthodontics, and Public Health, Bauru School of Dentistry, University of São Paulo, Bauru, São Paulo, Brazil. 5. Department of Dentistry, State University of Maringá, Maringá, PR, Brazil. 6. Department of Surgery, Stomatology, Pathology, and Radiology, Bauru School of Dentistry, University of São Paulo, Bauru, São Paulo, Brazil.
Abstract
INTRODUCTION: The purpose of this study was to evaluate the accuracy of small-volume cone-beam computed tomography (CBCT) to detect and measure isthmi in the apical root canals of mandibular molars by using micro-computed tomography (μ-CT) as the reference standard. METHODS: Forty mandibular first molars selected on the basis of μ-CT scan and presenting isthmi in the apical 3-mm mesial roots were scanned by using the highest-resolution settings of a small-volume CBCT unit. Isthmi lengths were measured and compared between both μ-CT and CBCT images to study the accuracy of CBCT readings. Quantitative data for sensitivity rate were depicted as percentage value with 95% confidence interval. Results were analyzed by using linear regression between true lengths (μ-CT) and CBCT lengths, Bland-Altman plot and t test, at α = 0.05. RESULTS: CBCT sensitivity for isthmi detection was 65% (95% confidence interval, 0.4667-0.8333). An average of 74.7% of the lengths could be measured, and differences among the lengths in μ-CT and CBCT were significant (P < .05; mean, 0.756 ± 0.655; t test), showing that there was no agreement between both methods. CONCLUSIONS: Accuracy of identifying apical isthmi of mandibular molars was highly influenced by the evaluation method. Small-volume CBCT imaging could not detect and measure apical isthmi length accurately. Moreover, using high-resolution settings in CBCT, it was not reliable to forecast the actual apical root canal anatomy.
INTRODUCTION: The purpose of this study was to evaluate the accuracy of small-volume cone-beam computed tomography (CBCT) to detect and measure isthmi in the apical root canals of mandibular molars by using micro-computed tomography (μ-CT) as the reference standard. METHODS: Forty mandibular first molars selected on the basis of μ-CT scan and presenting isthmi in the apical 3-mm mesial roots were scanned by using the highest-resolution settings of a small-volume CBCT unit. Isthmi lengths were measured and compared between both μ-CT and CBCT images to study the accuracy of CBCT readings. Quantitative data for sensitivity rate were depicted as percentage value with 95% confidence interval. Results were analyzed by using linear regression between true lengths (μ-CT) and CBCT lengths, Bland-Altman plot and t test, at α = 0.05. RESULTS: CBCT sensitivity for isthmi detection was 65% (95% confidence interval, 0.4667-0.8333). An average of 74.7% of the lengths could be measured, and differences among the lengths in μ-CT and CBCT were significant (P < .05; mean, 0.756 ± 0.655; t test), showing that there was no agreement between both methods. CONCLUSIONS: Accuracy of identifying apical isthmi of mandibular molars was highly influenced by the evaluation method. Small-volume CBCT imaging could not detect and measure apical isthmi length accurately. Moreover, using high-resolution settings in CBCT, it was not reliable to forecast the actual apical root canal anatomy.