Evaluation of the physicomechanical properties and biocompatibility of low-viscosity denture base resins for 3D printing

Three-dimensional (3D) printing has rapidly emerged as a transformative manufacturing technology in prosthodontics. However, the clinical application of 3D-printed denture base resins remains limited by insufficient mechanical properties and high viscosity. This study evaluated the physicomechanical properties and biocompatibility of four experimental 3D-printed denture base resins (T1-T4) formulated using bisphenol A-glycidyl dimethacrylate (Bis-GMA), urethane dimethacrylate (UDMA), and multifunctional acrylates. A commercial resin for 3D printing (T0; NextDent Base, Vertex Dental, Soesterberg, Netherlands) served as the control. The viscosity of each group was evaluated, and specimens were printed using a digital light-processing (DLP) 3D printer. Flexural strength, flexural modulus, and bond strength to artificial teeth were measured using a universal testing machine at a crosshead speed of 5 mm/min. Cell viability was assessed by the MTT assay using L929 cells. Data were analyzed using one-way analysis of variance and Scheffe post-hoc test ( α = 0.05). All experimental resins exhibited significantly lower viscosity than T0 ( p < 0.05). The T3 formulation demonstrated the highest flexural strength ( p < 0.05), and all experimental resins showed significantly higher flexural modulus than T0 ( p < 0.05). The bond strength of the experimental groups to artificial teeth was not significantly different from that of T0 ( p > 0.05), with all fracture patterns being cohesive or mixed. No groups showed cytotoxicity. The experimental denture base resins, particularly the T3 formulation, offered a higher flexural modulus and lower viscosity than the commercial resin while bond strength and biocompatibility were not significantly different from the control. Therefore, the experimental formulations are candidate compositions for further development toward a temporary denture base.