Yttrium tetragonal zirconia polycristal (Y-TZP) is a promising material that presents hydrothermal instability at low temperature due to metastable transformation of the tetragonal to monoclinic phase. This may lead to low temperature degradation (LTD), eventually compromising the mechanical properties and reliability of prosthetic treatments in the long-term. This project aims to innovate in the synthesis of a polycrystalline composite comprised by 80% alumina reinforced with 20% translucent (40 nanometer particle size) zirconia (ZTA - zirconia toughened alumina) and to characterize its mechanical properties in the nanoscale by nanoindentation, to assess its homogeneity throughout its bulk when compared to an experimental translucent zirconia. The specimens will be evaluated by nanoindentation testing, before and after a simulated LTD challenge. Surface 3D properties (Sa, Sq) will be characterized by interferometry to detect potential alterations such as grain extrusion after simulated LTD. The overall aim of the project is to develop a polycrystalline composite for dentistry that meets the best properties of both alumina and zirconia resulting in a material with improved mechanical resistance compared to alumina and more resistant to LTD compared to zirconia. Nanoindentation and interferometry testing are the proposed methodology to be performed at the Department of Biomaterials and Biomimetics, New York University (NYU), since sample preparation, equipment, and trained faculty will be available for successful project completion. The BEPE phase of the project will be of utmost importance considering that subsequent testing to be performed in Brazil rely on the understanding of the experimental materials properties at the nanoscale, which could be accurately performed and interpreted by equipments and faculty located at NYU. In addition, the data collected in this BEPE proposal would highly enrich the grant Jovem Pesquisador (#2012-19078-7) since it would validate the methods under use for polycrystalline composite fabrication.
News published in Agência FAPESP Newsletter about the scholarship: