Structure and Properties of 3D Printed Zirconia Applied in Dentistry

Abstract

During the last years, the interest in the application of the additive manufacturing (AM), also known as 3D printing, becomes extremely popular in the various fields of the medicine including the dentistry. Currently, metal and ceramic materials are most often used for dental prosthetics manufactured by 3D printing. The yttria-stabilized zirconia (YSZ) ceramics has become the best alternative for metal-based dental restorations. In this regard, the main goal of this review deals with studying the effect of the 3D printing parameters on the macro- and microstructure and, accordingly, on the mechanical properties of the sintered YSZ, and on this basis, to give the practical recommendations to clinical dentistry and further prospects. As most researched in recent years, the 3D printing methods of such ceramics are the Laser-Stereolithography (Laser-SL) and the Stereolithography-Digital Light Processing (SL-DLP) based on the vat-photopolymerization technology and are discussed here. The physical foundations and the technological parameters of these AM technologies are considered. The main attention focuses on the effects of the thermal conditions during the 3D printing on the solidification microstructure (density, grain size, and crystalline phase composition), which is controlled by the manufacturing technologies. In addition, the true hardness and the biaxial flexural strength of the 3D printed YSZ samples are discussed. At last, the advantages of 3D printing ceramics in dentistry are mentioned.