ABSTRACT
Purpose@#The aim of this study was to evaluate the influence of voxel size and different post-processing algorithms on the analysis of dental materials using micro-computed tomography (micro-CT). @*Materials and Methods@#Root-end cavities were prepared in extracted maxillary premolars, filled with mineral trioxide aggregate (MTA), Biodentine, and Intermediate Restorative Material (IRM), and scanned using micro-CT. The volume and porosity of materials were evaluated and compared using voxel sizes of 5, 10, and 20 µm, as well as different software tools (post-processing algorithms). The CTAn or MeVisLab/Materialise 3-matic software package was used to perform volume and morphological analyses, and the CTAn or MeVisLab/Amira software was used to evaluate porosity. Data were analyzed using 1-way ANOVA and the Tukey test (p<0.05). @*Results@#Using MeVisLab/Materialise 3-matic, a consistent tendency was observed for volume to increase at larger voxel sizes. CTAn showed higher volumes for MTA and IRM at 20 µm. Using CTAn, porosity values decreased as voxel size increased, with statistically significant differences for all materials. MeVisLab/Amira showed a difference for MTA and IRM at 5 µm, and for Biodentine at 20 µm. Significant differences in volume and porosity were observed in all software packages for Biodentine across all voxel sizes. @*Conclusion@#Some differences in volume and porosity were found according to voxel size, image-processing software, and the radiopacity of the material. Consistent protocols are needed for research evaluating dental materials.
ABSTRACT
PURPOSE: The aim of this study was to investigate the use and acceptance of digital radiographic examinations by Brazilian dental practitioners in daily practice and to evaluate the advances that have occurred over the past 5 years. MATERIALS AND METHODS: Dental practitioners enrolled in extension courses at the Piracicaba Dental School, University of Campinas, Brazil, responded to a self-administered questionnaire in the years 2011 and 2015. They were asked about sociodemographic factors and their knowledge and use of digital radiographic examinations. Descriptive analysis was performed, as well as the chi-square and Fisher exact tests, with a significance level of 5% (α=0.05). RESULTS: A total of 181 participants responded to the questionnaire in the years 2011 and 2015. Most of the respondents worked in private practice, had graduated within the last 5 years, and were between 20 and 30 years old. In 2011, 55.6% of respondents reported having ever used digital radiographic examinations, while in 2015 this number increased significantly to 85.4% (p<.0001), out of which 71.4% preferred it to conventional images. Moreover, 21.4% of respondents reported having used digital radiographic examinations for more than 3 years. A significant increase in use of intraoral digital radiography (p=0.0316) was observed in 2015. In both years, image quality and high cost were indicated, respectively, as the main advantage and disadvantage of digital radiographic examinations. CONCLUSION: This study showed that digital radiology has become more common in Brazil over the past 5 years. Most of the Brazilian dental practitioners evaluated in 2015 used digital radiographic examinations.
Subject(s)
Humans , Brazil , Dentists , General Practice, Dental , Private Practice , Radiographic Image Enhancement , Schools, Dental , Surveys and QuestionnairesABSTRACT
PURPOSE: This study was performed to assess the reproducibility of identifying the sella turcica landmark in a threedimensional (3D) model by using a new sella-specific landmark reference system. MATERIALS AND METHODS: Thirty-two cone-beam computed tomographic scans (3D Accuitomo(R) 170, J. Morita, Kyoto, Japan) were retrospectively collected. The 3D data were exported into the Digital Imaging and Communications in Medicine standard and then imported into the Maxilim(R) software (Medicim NV, Sint-Niklaas, Belgium) to create 3D surface models. Five observers identified four osseous landmarks in order to create the reference frame and then identified two sella landmarks. The x, y, and z coordinates of each landmark were exported. The observations were repeated after four weeks. Statistical analysis was performed using the multiple paired t-test with Bonferroni correction (intraobserver precision: p50% precision in locating the landmark within 1 mm. CONCLUSION: A newly developed reference system offers high precision and reproducibility for sella turcica identification in a 3D model without being based on two-dimensional images derived from 3D data.