Purpose: To investigate the optimal post-polymerization temperature and time to enhance the mechanical properties of three-dimensional (3D)-printed nanocomposites. Methods: A control group of pure 3D-printed resin was used to fabricate specimens post-polymerized at 40 °C for 15 min (n = 6). Next, 3-wt% functionalized yttria-stabilized zirconia (YSZ) nanoparticles were dispersed in a 3D-printed resin to fabricate YSZ-based nanocomposites for the experimental groups. The post-polymerization conditions of six experimental groups (n = 6) were set as two temperatures (40 °C and 80 °C) and three time periods (30, 60, and 90 min). The degree of conversion (DC), flexural strength, modulus, fractography, and hardness values of each group were evaluated. One-way and two-way analysis of variance were applied to analyze significant differences among the control and experimental groups and interaction effect of temperature and time of post-polymerization, respectively (α = 0.05). Results: Significant reductions in DC values were noted in the experimental groups compared to the control group. The experimental groups demonstrated significantly higher flexural strengths and moduli than those of the control group. At 80 °C, no significant differences were observed for different post-polymerization times. Compared to post-polymerization at 40 °C, the flexural strength, modulus, and hardness were significantly enhanced when the post-polymerization temperature was increased to 80 °C. Conclusions: Optimal mechanical properties of 3D-printed YSZ-based nanocomposites could be achieved under post-polymerization at 80 °C and 30 min.
Qi et al. (Tue,) studied this question.