Clarissa Teles Rodrigues1, Reinhilde Jacobs2,3,4, Karla Faria Vasconcelos2,3, Paul Lambrechts5,6, Izabel Regina Fisher Rubira-Bullen7, Hugo Gaêta-Araujo8, Christiano Oliveira-Santos9, Marco Antonio Hungaro Duarte1. 1. Department of Restorative Dentistry, Endodontics and Dental Materials, Bauru School of Dentistry, University of São Paulo, São Paulo, Brazil. 2. Department of Imaging and Pathology, Faculty of Medicine, OMFS IMPATH Research Group, KU Leuven, Leuven, Belgium. 3. Department of Oral and Maxillofacial Surgery, University Hospitals Leuven, Leuven, Belgium. 4. Department of Dental Medicine, Karolinska Institutet, Stockholm, Sweden. 5. Department of Oral Health Sciences, Endodontology, KU Leuven and Dentistry, University Hospitals Leuven, Leuven, Belgium. 6. Biomaterials-BIOMAT, Leuven, Belgium. 7. Department of Surgery, Stomatology, Pathology and Radiology, Bauru School of Dentistry, University of São Paulo, São Paulo, Brazil. 8. Division of Oral Radiology, Department of Oral Diagnosis, Piracicaba Dental School, University of Campinas, São Paulo, Brazil. 9. Department of Stomatology, Public Oral Health, and Forensic Dentistry, School of Dentistry of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil.
Abstract
OBJECTIVES: To evaluate the influence of artefacts in cone beam CT (CBCT) images of filled root canals in isthmus-containing molars. METHODS: 10 teeth presenting canals with an isthmus were instrumented and filled with a thermoplasticised obturation technique. The teeth were scanned using a micro-CT device and two CBCT devices: 3D Accuitomo 170 (ACC) and NewTom VGi evo (NT), with different acquisition protocols: larger and smaller voxel size. Three examiners assessed the CBCT images for: (1) detection of filling voids; (2) assessment of under- or overestimation of the filling material and (3) resemblance of CBCT images to the reference standard. Analyses of Task 1 yielded accuracy, sensitivity and specificity for detection of filling voids. For tasks 2 and 3, statistical analysis was performed using Wilcoxon test. The level of significance was set at p < .05. RESULTS: For Task 1, ACC showed higher sensitivity, whereas NT presented higher specificity. No significant difference was found between the protocols in ACC, however, for NT, differences between protocols were significant for all diagnostic values. In Task 2, visualisation of the filling was overestimated for NT, while for ACC, underestimation was observed. For Task 3, images with smaller voxel size were more similar to the reference image, for both CBCT devices. CONCLUSIONS: Different artefacts compromise the detection of filling voids on CBCT images of canals in mandibular molars with isthmus. ACC and NT present rather similar diagnostic accuracy, even though artefact expression remains device-specific.
OBJECTIVES: To evaluate the influence of artefacts in cone beam CT (CBCT) images of filled root canals in isthmus-containing molars. METHODS: 10 teeth presenting canals with an isthmus were instrumented and filled with a thermoplasticised obturation technique. The teeth were scanned using a micro-CT device and two CBCT devices: 3D Accuitomo 170 (ACC) and NewTom VGi evo (NT), with different acquisition protocols: larger and smaller voxel size. Three examiners assessed the CBCT images for: (1) detection of filling voids; (2) assessment of under- or overestimation of the filling material and (3) resemblance of CBCT images to the reference standard. Analyses of Task 1 yielded accuracy, sensitivity and specificity for detection of filling voids. For tasks 2 and 3, statistical analysis was performed using Wilcoxon test. The level of significance was set at p < .05. RESULTS: For Task 1, ACC showed higher sensitivity, whereas NT presented higher specificity. No significant difference was found between the protocols in ACC, however, for NT, differences between protocols were significant for all diagnostic values. In Task 2, visualisation of the filling was overestimated for NT, while for ACC, underestimation was observed. For Task 3, images with smaller voxel size were more similar to the reference image, for both CBCT devices. CONCLUSIONS: Different artefacts compromise the detection of filling voids on CBCT images of canals in mandibular molars with isthmus. ACC and NT present rather similar diagnostic accuracy, even though artefact expression remains device-specific.
Authors: L M Resende; F J A Rached-Junior; M A Versiani; A E Souza-Gabriel; C E S Miranda; Y T C Silva-Sousa; M D Sousa Neto Journal: Int Endod J Date: 2009-06-22 Impact factor: 5.264