The processing-related fracture resistance and reliability of root dental posts made from Y-TZP

In this study we have looked at how the processing affects the mechanical properties and reliability of root dental posts (RDPs) with a core that are made of yttria partially stabilized tetragonal zirconia (Y-TZP). These RDPs were designed for the aesthetic restoration of endodontically treated teeth. Low-pressure powder injection molding (LPIM) was used to wet form the green parts. The production process was found to have a significant effect on the mechanical properties and the Weibull modulus of the sintered specimens. During the shaping process different types of defects are introduced. These defects have a major effect on the reliability of the sintered specimens. A microstructural analysis of the sintered specimens was carried out to map these characteristic defects. With an appropriate adjustment of the molding parameters it was possible to eliminate most of these defects, and better reliability was achieved. ition, the effect of HIPing the sintered specimens was investigated. The results showed the importance of this post-sintering processing step on the reliability and fracture strength of the prepared parts.