Libros

This article presents a summary of 3D printers and the materials used. It was previously published in 3D Printing in Dentistry 2019/2020 by Irfan Ahmad and Fahad Al-Harbi, Quintessence Publishing. The article has been shortened and contains the orthodontic-relevant topics. Palabras clave: 3D printing, 3D printer materials, CAD/CAM, materials

The purpose of this in vitro study was to measure the marginal and internal fit of single-unit all-ceramic zirconia copings (ZCs) fabricated through three different computer-aided design/computer-assisted manufacture (CAD/CAM) systems using microcomputed tomography (microCT). A total of 10 ZCs were produced for each experimental group. Scanning of the stainless steel (SS) model with its respective copings was conducted with a SkyScan machine. DataViewer software was used to acquire cross-sectional images. Locations of cross-sections for all specimens were standardized to reduce errors. Seven different cross-section locations were selected: four transverse and three sagittal. Adobe Photoshop CS3 was used for the measurements. One-way analysis of variance and Tukey post hoc test were used for the statistical analysis for each group. In addition, t test (α = .05) was used to compare values at each measurement location for the different groups. The results of this study show significant differences in the precision of fit of the experimental groups at the axio-occlusal transition (AOT) location, with a significant gap present in the DeguDent CAD/CAM System compared to the other two systems. Tukey test results indicate a significant difference in the marginal gap between the DeguDent CAD/CAM System and KaVo Everest Dental CAD/CAM System (P = .004). In addition, there is a significant difference in gap size values in the sagittal sections distal to the midline between the DeguDent CAD/CAM System and the Lava Ultimate CAD/CAM System (P = .002). The different CAD/CAM systems showed a clinically acceptable internal fit and marginal adaptation. Different levels of fit were found between the experimental groups. Marginal adaptation was the best in all experimental groups. The gap at the AOT area varied among the three groups, with the DeguDent CAD/CAM System showing the greatest value.

Purpose: This study clinically and radiographically investigated the potential of platelet-rich plasma (PRP) gel combined with bovine-derived xenograft to treat dehiscence defects around immediate dental implants. Materials and Methods: This study was performed on 32 sites from 16 patients who each received an immediate implant for a single tooth replacement at a maxillary anterior or premolar site. Patients were divided into two groups according to the augmented materials used. One group received an immediate implant and filling of defects using a PRP gel plus bovine-derived xenograft. The other group received an immediate implant and filling of defects with a bovine-derived xenograft without PRP gel. Cone beam computed tomography (CBCT) was taken before placement, and at 6 and 12 months postsurgery. Results: Both treatment procedures resulted in significant improvements for the primary outcome regarding bone fill, as well as the marginal bone level. In addition, statistically significant differences were found in the bone density for the combined therapy compared with sites treated with bovine-derived xenografts alone (P ≤ .01). Conclusion: Autogenous PRP gel combined with bovine-derived xenograft demonstrated superiority to the bovine-derived xenograft alone, which suggested that it could be successfully applicable for the treatment of dehiscence around an immediate dental implant. Moreover, CBCT can be used to measure dehiscence and to assess bone thickness along the implant. Palabras clave: bone graft, buccal dehiscence, dentistry, immediate implant, platelet-rich plasma gel