This study compares the mechanical properties of photosensitive resins and thermoplastic filaments for the manufacturing of orthopedic devices using additive 3D printing. A mechanical characterization was conducted on different materials, including ABS, PETG, PLA, carbon fiber-reinforced PLA (PLA-CF), and SLA resin, employing Fused Deposition Modeling (FDM) and Stereolithography (SLA) techniques. Tensile tests were performed according to standardized norms to evaluate strength and elongation properties, analyzing the influence of material type, printing parameters, and layer thickness. The results indicate that PLA exhibits the highest mechanical strength (≈50 MPa), outperforming PLA-CF (≈40 MPa), ABS, and PETG (≈35 MPa). In contrast, SLA resin showed the lowest tensile strength (<20 MPa), highlighting a significant difference in performance between filament-based and resin-based materials. While PETG and PLA-CF demonstrated superior elongation, especially with a 0.2 mm extrusion diameter, SLA resin exhibited limited deformation capabilities. Printing orientation had a minor impact on mechanical properties, with slight variations in tensile strength and elongation. The findings suggest that thermoplastic filaments, particularly PLA and its composites, offer superior mechanical properties compared to SLA resins for load-bearing orthopedic applications. However, SLA resins provide advantages in surface finish and intricate detailing, which may be beneficial for specific medical applications. The study highlights the trade-offs between these two additive manufacturing approaches, contributing to the selection of optimal materials for customized orthopedic device fabrication.