This pilot study assesses the accuracy of 2 bone-supported stereolithographic surgical templates with respect to placement of implants in originally planned positions, and it tests the precision of dental volumetric tomography planning. Two mandibles retrieved from formalin-fixed human cadavers were scanned by dental volumetric tomography for planning of the implant positions, leading to stereolithographic models and fabrication of surgical guides. The situation immediately following drilling and implant insertion by an experienced surgeon was scanned and the outcome compared with the initial planning. The 3-dimensional discrepancies were then analyzed and determined. The results show deviations of the placed implants from the original planning, especially in the vertical direction, making the seating of a prefabricated denture impossible. At present, the flapless surgery technique based on stereolithographic surgical templates appears unsafe; further improvement is required.