Avaliação volumétrica de lesões periapicais simuladas – estudo in vitro

Abstract

Apical periodontitis is an evolution of pulpal necrosis, characterized by bone resorption in the apical region of a tooth. There are diverse methods for diagnosing and monitoring these lesions, being periapical radiographs the most used. Over the years, the use of computed tomography (CT) scans in Dentistry has spread, especially since the advent of Cone-Beam Computed Tomography (CBCT), due to its low radiation dose when compared to Multidetector CT (MDCT). However, new studies have proposed the use of MDCT for the maxillofacial region using a lower radiation dose protocol. Therefore, the objective of this study was to evaluate the accuracy of low-dose MDCT for volumetric measurement of simulated periapical lesions, comparing it with standard MDCT protocol and with CBCT protocols. Eighteen monoradicular teeth were included into simulated alveoli in five bone blocks; periapical lesions were simulated in the periapical region of these alveoli. Four acquisition protocols were used: small FOV CBCT (90kV, 10mA, 0,2mm-voxel), full FOV CBCT (120kV, 5mA, 0,2mm-voxel), standard MDCT (120kV, 50mA, 0,62mm-voxel), and low-dose MDCT (120kV, 10mA, 0,62mm-voxel). All DICOM images were evaluated by a single trained and calibrated examiner (ICC = 0.991) using ITK-SNAP segmentation software. The gold standard was obtained by the impressions of the lesions with regular fluid addition silicone and individual weighing using a precision analytical balance. Data were evaluated by one-way ANOVA test; the significance level was P <0.05. As results, no statistical differences (p = 0.975) were found among the four protocols, regarding the tomography device, FOV, or voxel size. Low-dose MDCT presented similar performance to the other reference standard methods for measuring the volume of bone cavities, of interest of the dentist.