Mechanical and Light Transmission Properties of 3D-Printed Dental Resins

Objectives: The aim was to evaluate the physical, mechanical, and light transmission properties of four 3D-printed resins used for dental crown: Ceramic Crown - SprintRay (CC), ONX Tough 2 - SprintRay (OT2), Sculpture 2.0 - Rodin (S2) and Voxel Print - FGM (VP).
Methods: Flexural strength (FS, MPa), elastic modulus (E, GPa), compressive strength (CS, MPa), ultimate tensile strength (UTS, MPa), Vickers hardness (VH, N/mm2), water sorption (Wsp, μg/mm3), and surface roughness (Ra, μg) were evaluated.Power (mW), radiant spectral (mW/nm), and beam profile were recorded with 4 thicknesses (0.3, 0.5, 1.0, 1.5, and 2.0 mm) emitted by different light-curing units (LCUs): Elipar DeepCure-S, Bluephase, and VALO Grand. Data were analyzed using one-way ANOVA (α = 0.05).
Results: The vales for FS (MPa) were- CC:144.2, OT2:118.9, S2:108.48 and VP:117.21; UTS were- CC:64.7, OT2:68.4, S2:37.6, and VP:116.5; E were- 6.8, OT2:2.3, S2:4.9 and VP:3.9. The CS (MPa) and VH (N/mm2) were higher for VP (CS:347.4; VH 44.4) CC (CS: 209.5; VH 38.8); S2 (CS: 205.4; VH: 41.5) and OT2 (CS:124.0; VH: 31.1). Wsp and Ra values were similar for all resins (P<0.05). As the thickness increased, exponential reduction ofpower and spectral radiant power were observed (P<0.001). VP and CC demonstrated higher light transmission at 0.3 mm and 0.5 mm thicknesses. S2 exhibited greater attenuation. All resins showed similar Wsp. VP and CC achieved better light transmission in thinner specimens. Greater light attenuation was found for S2.
Conclusions: The 3D-printed resins presented properly mechanical and aesthetics for producing dental crowns. The light transmission properties of 3D printed resin should be observed for optimizing the photopolymerization.