Propriedades mecânicas de restaurações obtidas por impressora 3D

Abstract

In the context of modern clinical practice, the use of digital workflows for obtaining dental restorations has gained prominence, offering benefits such as speed, precision, cost reduction, and increased patient comfort. Advances in printing technologies have enabled the application of resins in rehabilitation processes, aiming to enhance resistance and extend the lifespan of restorations through the incorporation of ceramic microparticles and zirconia oxide. This thesis addressed three specific objectives in this field. The first objective involved evaluating the physical and mechanical properties of four printed resins at two different layer thicknesses. This included the analysis of conversion degree through Raman spectroscopy, surface roughness through confocal microscopy and scanning electron microscopy, flexural strength through three-point testing, and modulus of elasticity using a universal testing machine, as well as Vickers hardness through a microdurometer. The second objective focused on analyzing the composition, macro, and microstructure of the four resins, employing techniques such as Raman spectroscopy for spectrum acquisition, Energy Dispersive X-ray Spectroscopy (EDS) for composition, and Scanning Electron Microscopy and confocal microscopy for macro and microstructure evaluation. The third objective involved assessing the survival of implant-supported single crowns through a prospective cohort study with 33 patients and 76 installed crowns. The data were properly analyzed, considering a significance level of 0.05. The results indicated that the resins used and different layer thicknesses directly influenced most of the conducted tests. Higher values of flexural strength were observed, while lower values of surface roughness were found in specimens printed with a smaller layer thickness. The composition and structure of microparticles proved to be influential factors in the mechanical properties of the resins. Although the survival rate of crowns was relatively low in the analyzed periods, the technique showed promise for the fabrication of immediate provisional restorations.