Aim: The aim of this study was to evaluate the flexural strength properties of three different aged and nonaged 3D-printed resins built by different 3D printing systems used in dental applications. Materials and Methods: Bars (2 × 2 × 25 mm) were additively fabricated using a 3D printer and different dental crown resins (Saremco Crowntec, Senertek P-Crown V2, and Senertek P-Crown V3) per the manufacturers’ recommendations. Each subgroup was divided into aged and nonaged subgroups (n = 10 bars per group). Thermocycling procedures (5º to 55ºC; 5,000 cycles) were performed under favorable conditions for the aged subgroups from each material. Flexural strength (MPa) was measured in all samples using a universal test machine. Results: When both aged and nonaged resins are compared, significant differences were found in flexural strength measurements (P < .001). The highest flexural strength was observed in the Saremco Crowntec group, while the lowest flexural strength was observed in the Senertek P Crown V2 group. The flexural strength measurements of Saremco Crowntec and Senertek P Crown V3 displayed no significant difference between their aged and nonaged groups (P > .05), while Senertek P Crown V2 (P = .039) showed significant differences between its aged and nonaged groups. Conclusions: Saremco Crowntec showed the highest flexural strength both in aged and nonaged groups, while Senertek P Crown V2 had the lowest strength. The artificial aging process decreased flexural strength values in all 3D-printed resin groups.