Keynote Address: Sandblasting of Dental Zirconia: an Engineering Perspective

Zirconia-based dental restorations are manufactured to serve in the aggressive environment of the oral cavity for a certain period of time, which normally spans 7-12 years. In order to obtain a high and durable bonding of dental cement to a chemically inert zirconia framework, the bonding surface should be cleaned and roughened, which is commonly achieved using sandblasting with 50–110-µm airborne particles at a moderate pressure. Since tetragonal zirconia exhibits a stress-induced transformation, the abraded surface will be not only damaged but also constrained. The phase transformation contributes to the surface strengthening and enhanced ageing resistance, whereas impact-induced surface flaws act as the stress concentrators that may become strength determining. In this lecture, the sandblasting of dental zirconia ceramics will be elucidated from an engineering perspective, i.e., by considering the impact energy as a function of the process variables on the one hand, and the material’s response on the other.