Percorrer por autor "Vasconcelos, Isabel"
A mostrar 1 - 2 de 2
Resultados por página
Opções de ordenação
- 3D-printed multisampling holder for microcomputed tomography applied to life and materials science researchPublication . Vasconcelos, Isabel; Franco, Margarida; Pereira, Mário; Duarte, Isabel; Ginjeira, António; Alves, NunoThe aim of this work was to design, fabricate, test and validate a 3D-printed multisampling holder for multi-analysis by microcomputed tomography. Different raw materials were scanned by microcomputed tomography. The raw material chosen was used to fabricate the holder by 3D printing. To validate the multisampling holder, five teeth were filled with a high density-material and scanned in two ways: a single and a multisampling scan mode. For each tooth, the root canal filling volume, porosity volume, closed pore volume, and open pore volume were calculated and compared when the same tooth was scanned in the two sampling scan mode. ABSplus P430™ allowed a high transmission value (84.3 %), and then it was the polymeric material selected to fabricate the holder. In a single sampling scan mode, the scan duration for scanning five teeth was 87.42 min, contrasting with 21.51 min for a multisampling scan mode, which scanned five teeth at the same time. The scan duration time and the cost using a multisampling holder represented a reduction of 75 % and the data volume generated represented a reduction of 60 %. Comparing the two scan modes, the results also showed that the difference of root canal filling volume, porosity volume, closed pore volume, and open pore volume was not statistically significant (p > .05). The multisampling holder was validated to do multi-analysis by microcomputed tomography without significant loss of quantitative accuracy data, allowing a reduction in scan duration time, imaging cost, and data storage.
- Evaluation of Root Canal Filling with a Bioceramic Sealer Using Micro-Computed Tomography: A Pilot StudyPublication . Vasconcelos, Isabel; Pereira, Mário Rito; Ginjeira, António; Franco, Margarida; Morouço, Pedro; Alves, NunoThis pilot study aims to define a protocol for optimizing the micro-computed tomography (micro-CT) settings to evaluate in the future research the root canal filling in oval shaped canals. Thirty distal canals of mandibular molars were used. After preparation of the canals, the roots were randomly divided into five groups. The canals were filled with two types of sealers (Endosequence BC Sealer or AH Plus) and two types of gutta percha (Protaper Next cones and Endosequence BC cones), using thermal obturation in comparison with a single cone obturation technique. Each specimen was scanned three times using a micro-CT device at a resolution of 30,1 μm. The first scan was done for selecting the specimen according the inclusion criteria, the second one postinstrumentation and the last micro-CT scan after obturation the specimens. For the present study, the images were only evaluated with qualitative criteria and the settings for acquisition, reconstruction and analysis of micro-CT images were tested.