External cervical resorption: a three-dimensional classification

To estimate the absorbed organ dose and effective dose for a wide range of cone beam computed tomography scanners, using different exposure protocols and geometries. Two Alderson Radiation Therapy anthropomorphic phantoms were loaded with LiF detectors (TLD-100 and TLD-100 H) which were evenly distributed throughout the head and neck, covering all radiosensitive organs. Measurements were performed on 14 CBCT devices: 3D Accuitomo 170, Galileos Comfort, i-CAT Next Generation, Iluma Elite, Kodak 9000 3D, Kodak 9500, NewTom VG, NewTom VGi, Pax-Uni3D, Picasso Trio, ProMax 3D, Scanora 3D, SkyView, Veraviewepocs 3D. Effective dose was calculated using the ICRP 103 (2007) tissue weighting factors. Effective dose ranged between 19 and 368 μSv. The largest contributions to the effective dose were from the remainder tissues (37%), salivary glands (24%), and thyroid gland (21%). For all organs, there was a wide range of measured values apparent, due to differences in exposure factors, diameter and height of the primary beam, and positioning of the beam relative to the radiosensitive organs. The effective dose for different CBCT devices showed a 20-fold range. The results show that a distinction is needed between small-, medium-, and large-field CBCT scanners and protocols, as they are applied to different indication groups, the dose received being strongly related to field size. Furthermore, the dose should always be considered relative to technical and diagnostic image quality, seeing that image quality requirements also differ for patient groups. The results from the current study indicate that the optimisation of dose should be performed by an appropriate selection of exposure parameters and field size, depending on the diagnostic requirements. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved. Show more

Cone beam computed tomography (CBCT) produces undistorted three-dimensional information of the maxillofacial skeleton, including the teeth and their surrounding tissues with a lower effective radiation dose than computed tomography. The aim of this paper is to: (i) review the current literature on the applications and limitations of CBCT; (ii) make recommendations for the use of CBCT in Endodontics; (iii) highlight areas of further research of CBCT in Endodontics. Show more

To compare the accuracy of intraoral periapical radiography with cone beam computed tomography (CBCT) for the detection and management of resorption lesions. Digital intraoral radiographs and CBCT scans were taken of patients with internal resorption (n = 5), external cervical resorption (n = 5) and no resorption (controls) (n = 5). A 'reference standard' diagnosis and treatment plan was devised for each tooth. Sensitivity, specificity, positive predictive values, negative predictive values and receiver operator characteristic (ROC) curves, as well as the reproducibility of each technique were determined for diagnostic accuracy and treatment option chosen. The intraoral radiography ROC Az values were 0.780 and 0.830 for diagnostic accuracy of internal and external cervical resorption respectively. The CBCT ROC Az values were 1.000 for both internal and external cervical resorption. There was a significantly higher prevalence (P = 0.028) for the correct treatment option being chosen with CBCT (%) compared with intraoral radiographs (%). CBCT was effective and reliable in detecting the presence of resorption lesions. Although digital intraoral radiography resulted in an acceptable level of accuracy, the superior accuracy of CBCT may result in a review of the radiographic techniques used for assessing the type of resorption lesion present. CBCT's superior diagnostic accuracy also resulted in an increased likelihood of correct management of resorption lesions. Show more