Comparison of Mechanical and Surface Properties between Conventional and CAD/CAM Provisional Restorations

Objective This study compared the flexural strength, surface hardness, and surface roughness of conventional, milled, and three-dimensional (3D)-printed provisional restorations. Materials and Methods Bar-shaped polymethyl methacrylate (PMMA) specimens (25 x 2 x 2 mm(3)) and disc-shaped specimens (9 x 2 mm(2)) were fabricated using three different techniques (n = 10/group): conventional (SR Ivocron C&B, Ivoclar Vivadent, Schaan, Liechtenstein), milling (Aidite Temp PMMA Blocks, Aidite, Qinhuangdao, China), and 3D printing (Asiga DentaTOOTH, Asiga, Sydney, Australia). Flexural strength was evaluated using a universal testing machine until fracture occurred. Vickers hardness and surface roughness tests were performed on the disc-shaped specimens using a micro-Vickers hardness tester and atomic force microscopy, respectively. Statistical Analysis Data were statistically analyzed using one-way ANOVA. The post hoc Tukey's honest significant difference was conducted to compare the differences value between groups ( p < 0.05). Results The milled computer-aided design/computer-aided manufacturing (CAD/CAM) provisional restorative material exhibited a significantly higher flexural strength (125.16 +/- 6.83 MPa) compared with both the traditional (109.74 +/- 14.14 MPa) and 3D-printed (71.09 +/- 9.09 MPa) materials (p < 0.05). The conventional material had a higher Vickers hardness (19.27 +/- 0.41 kgf/mm(2)) compared with the milled (18.53 +/- 0.32 kgf/mm(2)) and 3D-printed (17.80 +/- 1.85 kgf/mm(2) ) materials, though the difference was statistically significant only between the conventional and 3D-printed groups. The surface roughness of the milled CAD/CAM material (8.80 +/- 2.70 nm) was significantly lower than that of the 3D-printed material (24.27 +/- 9.82 nm) ( p < 0.05). Conclusion The provisional restorations fabricated using milled PMMA technology provide adequate flexural strength, surface hardness, and low surface roughness, offering a viable alternative for creating provisional restorations.