Evaluation of Fracture Strength and Surface Topography of Interim Prosthodontics Fabricated Using 3D Printing Compared to CAD/CAM Systems (In-Vitro Study)

Background: In addition to the popularity of CAD/CAM milling systems, the use of 3D printing for the fabrication of interim prosthodontics has also become widespread. The materials used for 3D printing still need further investigation in regards to strength and surface topography. Objective: to evaluate fracture strength and surface topography of interim restorations fabricated by 3D printing systems compared to CAD/CAM milling systems. Materials and Methods: A preparation was performed on the first premolar and first molar of a mandibular typodont model cast, to resemble a three-unit all-ceramic fixed dental prosthesis (FDP). A digital design was then created using ExoCad software to create a digital master model. Two groups of interim fixed dental prosthesis (IFDP) were fabricated based on the virtual design. Group I: eight IFDP samples of polymethyl-methacrylate (PMMA) were milled using CAD/CAM. Group II: Eight IFDPs were 3D printed using PMMA resin. The surface topography of samples was measured using a surface profilometer. The fracture strengths of the IFDPs were then assessed by a universal testing machine. Results: The difference in surface topography between both groups was statistically non-significant as revealed by student t-test (P=0.4499>0.05). The milled group recorded higher mean value of fracture strength than the 3D printed group. Student t-test (P=