Characterization and optical properties of zirconia specimens and ultra-thin veneers fabricated by solvent-based slurry stereolithography with solvent and thermal debinding process

Abstract

The study investigated the viability of 3D-printed zirconia specimens created using solvent-based ceramic slurry stereolithography (3S), focusing on their utility in dental ultra-thin laminate veneers. Solvent debinding was employed to minimize defect risks, with the debinding process designed based on thermogravimetric analysis. The study evaluated how solvent debinding affected the microstructural and mechanical properties of the zirconia specimens. Optical properties of 0.1 mm and 0.3 mm thick ultra-thin veneers were characterized, focusing on color parameters and relative translucency (RTP00) values. Following solvent debinding, the green bodies exhibited noticeable surface pores, although this did not compromise density or dimensional accuracy. The sintered specimens treated with solvent debinding showed a slight increase in tetragonal phases, a significant reduction in surface roughness, and improvements in Vickers hardness and flexural strength. Cell viability tests confirmed more than 90% viability for NIH-3T3 cell lines, highlighting excellent biocompatibility. Veneers with a 0.1 mm thickness demonstrated RTP00 values between 16.57 and 19.38, and the shade of the dental substrate notably influenced their color. The study demonstrated that the solvent debinding process effectively reduced porosity, consequently improving the mechanical properties of specimens fabricated using the 3S technique. Ultra-thin zirconia veneers produced by this method exhibited high RTP00 values, indicating their potential suitability for anterior dental applications. Notably, the substrate shade emerged as a critical factor in achieving optimal aesthetic results.