engleski

The effect of Y3+ addition on morphology, structure, and electrical properties of yttria-stabilized tetragonal zirconia dental materials

Zirconia (ZrO2), a widely known material with an extensive range of applications, is espe- cially suitable for dental applications. This kind of dental material is produced in the form of blocks or discs (mostly discs—depending on CAD/CAM machines) by cold isostatic pressing (CIP). Such discs are subsequently milled by CAM/CAD technology into a desirable form. Due to the application of CIP, the resulting discs consist of different yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) powders, additives and pigments. The diverse composition of the discs (e.g., different Y3+ content) governs material properties, such as hardness, toughness and translucence. The aim of this work was to investigate the impact of Y3+ addition on the grains and grain boundaries, on the ZrO2 phases lattice parameter values and on the electrical equivalent circuit parameters of the prepared Y- TZP samples. The disc-shaped samples were prepared by using CAM/CAD technology. It was observed that the grain size and the grain density were increased by Y3+ addition. The sample with the lowest Y3+ content was characterized by the highest portion of the tetragonal phase, whilst the disc with the highest Y3+ addition consisted mainly of the cubic phase. It was also observed that at the higher Y3+ ion concentrations, these ions mainly incorporated the tetragonal phase. Furthermore, conductivity investigations showed that the resistivity of the grains in the samples with the higher Y3+ concentrations was decreased as these ions were mainly trapped in the grain boundary. On the other hand, the Y3+ trapping increased the capacitance of the grain boundary.

zirconia ; PXRD ; impedance ; EEC ; conductivity ; dental material

nije evidentirano