Purpose: To evaluate and compare the impact strength of 3D-printed resin to conventionally fabricated denture bases of heat-cure and cold-cure acrylic resin.
Materials and Methods: Denture base materials were evenly divided into three groups (n = 25 each; N = 75): (1) 3D-printed material (Denture Base LP, Formlabs Dental); (2) Heat-cure acrylic resin (Lucitone 199, Dentsply Sirona); and (3) cold-cure acrylic resin (Lucitone HIPA, Dentsply Sirona). The 3D-printed specimens were designed with the dimensions 64 × 12.7 × 3.2 mm using computer-aided design software, then printed with a desktop stereolithography printer (Form 2, Formlabs). Heat-cure and cold-cure acrylic resin specimens were fabricated through conventional (compression and pouring) methods. The impact energy was read directly from the impact tester in joules, and the cross-sectional area of each specimen was used to calculate the impact strength in kJ/m2. Analysis of variance, Tukey multiple comparisons test, and a likelihood ratio α = .05 were conducted.
Results: The average mean impact strength was 8.9 kJ/m2 for heat-cure acrylic resin, 11.2 kJ/m2 for 3D-printed resin, and 14.9 kJ/m2 for cold-cure acrylic resin. Tukey multiple comparisons test showed that the impact strength for the cold-cure group was significantly greater than for the 3D-printed resin and heatcure acrylic resin groups.
Conclusion: Within the limitations of this study, the cold-cure acrylic resin showed the greatest impact strength, followed by the 3D-printed resin and conventional heat-cure denture base materials, respectively.