Development of a Three-Dimensional Slurry Printing System Using Dynamic Mask Projection for Fabricating Zirconia Dental Implants

This study aims to develop a three-dimensional slurry printing system (3DSP) and to use a two-stage sintering process for the fabrication of zirconia dental implants. Solvent-soluble slurry which is composed of zirconia powder, visible light-curable resin, and methanol is prepared. During layer casting, the liquid slurry penetrates into the pores of the subjacent layers. The fresh layer and the subjacent layer tightly connect when the solvent dries. The mask pattern for the sliced layers is then exposed on a solvent-soluble slurry, for solidification and to form the green part that is embedded in the green block, layer-by-layer. The green block is immersed in a methanol solution, which causes the collapse of the un-exposed part. As a result, the rigid green part is obtained. Two-stage sintering is used to heat the rigid green part to 600°C to produce binder burnout and to 1450°C to sinter the zirconia dental implant part. The results show that sintered parts have an average flexural strength and micro-hardness of 539.1 MPa and 1556 HV, respectively. The zirconia dental implant is successfully fabricated using the 3DSP system developed. The proposed fabrication method using a 3DSP system is briefly described and it is proven that there is a good capacity to fabricate zirconia dental implants.