Optimizing Printing Temperature and Post-Curing Time for Enhanced Mechanical Property and Fabrication Reproducibility of 3D-Printed Dental Photopolymer Resins

This study aims to evaluate the effects of printing temperature and post-curing duration on double-bond conversion (DBC), mechanical properties, and fabrication reproducibility of three dental photopolymer resins used for fixed dental prostheses (FDPs), denture bases, and direct clear aligners. Specimens were fabricated using stereolithography and masked stereolithography three-dimensional (3D) printers at room temperature (RT, 28 °C) and 50 °C, then subjected to six post-curing durations: 0, 60, 120, 180, 240, and 600 s. DBC was measured using Fourier transform infrared spectroscopy, and tensile strength was measured using tensile testing. Furthermore, fabrication reproducibility for clinical applicability was analyzed using root mean square deviations from 3D scanning. Printing at 50 °C significantly improved the DBC, tensile strength, and fabrication reproducibility of FDP and denture base resins compared to printing at RT, enabling shorter post-curing times (p < 0.001). Clearer aligner resin specimens printed at 50 °C and post-cured for 120 s exhibited the highest fabrication reproducibility (p < 0.001), while tensile strength did not differ significantly from that of RT specimens post-cured for 240 s (p > 0.05). These findings suggest that optimizing printing temperature and post-curing time enhances the mechanical properties and fabrication reproducibility of 3D-printed dental materials.