Ceramic 3D printing using lithium silicate prepared by sol-gel method for customizing dental prosthesis with optimal translucency

Abstract

In dentistry, various ceramics have been tested to overcome the opacity of zirconia. Moreover, three-dimensional (3D) printing technology is being used to accurately reproduce intricate shapes and overcome material wastage. This study described the application of a lithium silicate 3D printing material for the fabrication of transparent ceramic dental prostheses and the optimization of the process. After synthesizing approximately 500 nm of lithium silicate powder using the sol-gel method, field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), were performed and rheological properties were evaluated. Then, the sintering conditions were set based on thermogravimetry differential thermal analysis (TG-DTA). A slurry for 3D printing containing 40 vol% powder along with a photocurable resin, an acrylate binder, and a dispersant was prepared. A specimen measuring 15 mm in diameter and 1.8 mm in height, with a layer thickness of 50 μm, was printed with a digital light process (DLP) 3D printer using different holding times (1, 3, 5, and 10 h) and at a final sintering temperature of 1325 °C among the preceding sintering conditions. The shrinkage rate, Vickers hardness, and translucency of the finished specimens were compared and analyzed. Our study terrified the possibility of 3D printing of lithium silicate. Furthermore, our results suggest that a long sintering holding time has a positive effect on the specimen characteristics.