Enhancing Wear Resistance and Surface Hardness of Three-Dimensionally Printed Denture Teeth Through Post-Treatment Under Elevated Temperature and Pressure

Abstract

Three-dimensionally (3D)-printed denture teeth are increasingly used in clinical practice; however, their wear resistance and surface hardness may be insufficient for long-term clinical application. Moreover, the effect of post-treatment under elevated temperature and pressure on these properties remains unclear. This study aimed to evaluate the effect of such post-treatment on the wear resistance and Vickers hardness of 3D-printed denture teeth resin. One hundred disk-shaped specimens (10 × 2 mm) were 3D-printed using Dima denture teeth resin and randomly assigned to four post-treatment groups (121 °C at 2 bar for 4, 30, 60, and 90 min) and one untreated control group. Within each group, specimens were allocated for wear resistance (n = 10) and Vickers hardness (n = 10) testing. Wear resistance was measured using an impact-sliding wear testing machine in a polymethyl methacrylate slurry, while Vickers hardness was measured using a hardness tester under a 50 g load with a 15 s dwell time. Statistical analyses included one-way analysis of variance (ANOVA), Kruskal–Wallis, and Welch’s ANOVA (α = 0.05). All post-treatment groups exhibited significantly lower depth loss and higher hardness than the control group (p < 0.05). Specimens post-treated for ≥30 min exhibited significantly lower volume loss than the control group (p < 0.05). The 121 °C/90 min group demonstrated the highest wear resistance and Vickers hardness. Within the limitations of this study, post-treatment under elevated temperature and pressure significantly improved the wear resistance and Vickers hardness of the tested 3D-printed denture teeth resin, with the 90 min protocol yielding the greatest enhancement. Thus, thermal-pressure post-treatment may be a promising approach for enhancing the mechanical performance of additively manufactured denture teeth.