Comparative evaluation of mechanical and physical properties of provisional crown and bridge materials fabricated using milling, three-dimensional printing and conventional methods: An in vitro study

AIM: To evaluate and compare the mechanical and physical properties of provisional crown and bridge materials fabricated using milling, three-dimensional (3D) printing, and conventional methods. SETTINGS AND DESIGN: This was a comparative in vitro study. MATERIALS AND METHODS: Six different provisional resin materials, with two commercial brands representing each fabrication technique (milled resins including Sagemax and Ruthinium, 3D printed resins including Dionavi and Ackudent, and conventionally fabricated cold-cure resins including Dental Products of India (DPI) and Cool Temp) were tested. A total of 210 samples were prepared, 35 from each material, using their respective fabrication methods. Based on the properties to be evaluated, the 35 samples were further divided into 5 subgroups, each with 7 samples (n = 7). The cylindrical-shaped samples (4 mm × 6 mm) were subjected to tests for compressive strength (CS) and diametral tensile strength (DTS). Rectangular samples (25 mm × 2 mm × 2 mm) were used to assess the flexural strength (FS) and the microhardness (MH). Additionally, disc-shaped samples (10 mm × 2 mm) were examined for physical properties, surface roughness (SR). STATISTICAL ANALYSIS USED: One-way analysis of variance and post hoc Tukey's tests were used. RESULTS: Both milled and 3D printed resin groups demonstrated significantly higher CS and FS (P = 0.001) except with 3D Ackudent. Significantly higher DTS and MH (P = 0.001) were found with both the milling and control groups compared to the 3D-printed resin groups. Control groups exhibited the highest SR (P = 0.022) compared to both milling and 3D printed groups. CONCLUSION: Milled provisional resins showed superior mechanical properties, with Sagemax showing the highest FS and MH, Ruthinium with the highest DTS. Both 3D printed resins exhibited the lowest DTS and MH, though 3D Dionavi showed higher CS compared to milled and conventional resins. The conventional resins showed lower FS than milled resins and 3D Dionavi but higher than 3D Ackudent. Both 3D printed and milled resins showed smoother surfaces than those of conventional provisional resins.