Improved mechanical performance and forming accuracy of ZrO2 fixed partial denture based on the digital light processing technology

Abstract

Fixed partial dentures are the primary treatment for dentition defects. Digital light processing (DLP) 3D printing technology is an advanced technique with significant advantages and potential in the field of dental restoration, particularly in cases requiring high precision and personalization. However, challenges persist in printing fixed partial dentures that meet the strength requirements for clinical applications. In this study, we aimed to optimize printing parameters, including exposure time and layer thickness, to enhance dimensional accuracy, reduce warpage, and improve the surface quality of the samples. Additionally, we focused on the rheological and curing properties of the paste. The optimal combination of printing parameters was found to be 5 s of exposure time and 50 μm layer thickness, achieving superior dimensional accuracy, reduced warpage, and improved surface quality. For a slurry with 40% solid content, the dispersant KOS 110 demonstrated the best shear thinning effect, with an optimal addition of 2%. Notably, the Vickers hardness, flexural strength, and fracture toughness of the ZrO₂ fixed partial dentures were 13.52 ± 0.21 GPa, 940 ± 20 MPa, and 6.92 ± 0.25 MPa·m1/2, respectively, which surpasses that of human enamel (4 GPa) and is comparable to CAD/CAM ZrO₂ (900–1200 MPa). This study demonstrates that DLP technology can be effectively used to fabricate ZrO₂ personalized complex fixed partial dentures with excellent mechanical properties and high precision, offering broad application prospects in stomatology.