Comparison of mechanical properties, surface roughness, and color stability of 3D-printed and conventional heat-polymerizing denture base materials

Studies on the mechanical, optical, and surface properties of 3-dimensionally (3D) printed denture base materials are scarce, and those available have reported conflicting results. The purpose of this in vitro study was to compare the mechanical properties, surface roughness, and color stability of 3D-printed and conventional heat-polymerizing denture base materials. A total of 34 rectangular specimens (64×10×3.3 mm) were fabricated from each of the conventional (SR Triplex Hot; Ivoclar AG) and 3D-printed (Denta base; Asiga) denture base materials. All specimens underwent coffee thermocycling for 5000 cycles, and half in each group (n=17) were evaluated in terms of color parameters, color change (ΔE00), and surface roughness (Ra) before and after coffee thermocycling. The specimens then underwent a 3-point bend test. The remaining specimens in each group (n=17) underwent impact strength and Vickers hardness testing. Data were analyzed by the paired samples, independent samples, and Wilcoxon signed rank tests (α=.05). The color change caused by coffee thermocycling in the 3D-printed group was higher than that in the conventional group (P