Influence of Nanoparticle-Sized Zirconia on Mechanical Properties and Material Characterization Towards Zirconia Blocks for Dental Restorations

Starting powder characteristics can have an impact on the final mechanical properties of a material. This is the same for a high-strength ceramic such as 3 mol% yttria-stabilized zirconia (3YSZ) in dental applications. Thus, this study aimed to investigate the impact of 3YSZ nanopowder particle size on its mechanical properties. 30 nm and 90 nm 3YSZ powder particle sizes were employed. 10 mm-diameter, 5 mm-high samples were prepared by colloidal processing, followed by cold isostatic pressing (CIP) and the sintering process. Finally, the sintered samples were characterized. In comparing the 90 nm and 30 nm starting powders, distinct differences emerge in their respective properties. The grain size of the 90 nm powder measured 303.6 nm, whereas the 30 nm powder exhibited a slightly larger size at 317.7 nm. Volumetric shrinkage for the 90 nm powder reached 40.3%, while the 30 nm powder had a shrinkage of 34.0%. The hardness of the 90 nm powder was measured at 14.6 GPa, slightly higher than the 14.4 GPa recorded for the 30 nm powder. Additionally, the fracture toughness of the 90 nm powder was 5.0 MPa.m<sup>1/2</sup>, whereas the 30 nm powder showed a slightly lower value of 4.9 MPa.m<sup>1/2</sup>. Both 90 nm and 30 nm 3YSZ powders showcased high mechanical properties, with slightly superior characteristics observed for the 90 nm particles. These findings underscore the nuanced impact of initial particle size on the material’s mechanical characteristics, emphasizing the importance of precision in powder engineering for optimizing material performance in various applications.