more predictable prosthetic outcomes than non-guided implant surgery. OBJECTIVES: To compare the accuracy of implant placement using 3D printed and machine milled surgical guides. MATERIALS AND METHODS: Twelve polyurethane foam resin mandibular models were used in this study. Implant position was virtually planned using 3D planning software based on the preoperative CBCT of each model. Surgical guides were designed on the software and exported in STL format. Models were randomly divided into 2 groups (n=6 each). Group I: Surgical guides were manufactured using 3D printing. Group II: Surgical guides were manufactured using machine milling. Three implants were placed in each model using CAD/CAM surgical guides. The 3D position of the planned and placed implants, in terms of the linear deviations of the implant head and apex and the angular deviations of the implant axis, was compared by superimposing the pre- and postoperative CBCT using dedicated software. The MannWhitney U test was used for comparison (P <0.05). RESULTS: The mean coronal, apical and angular deviation for Group I were 0.72 ± 0.21 mm, 1.1 ± 0.42 mm and 2.5° ± 1.2° respectively, while for Group II they were 0.85 ± 0.3 mm, 1.3 ± 0.37 mm and 3.09° ± 0.89° degrees respectively. No significant differences were found between both groups for any of the measurements. CONCLUSIONS: 3D printing gave better results over machine milling; however, both types can be used in manufacturing surgical guides as difference in accuracy is not statistically significant. The accuracy of implants in both groups was within the safety margin of previous studies.