The utilization of digital 3D surface images (STL format) for planning cases of computer-guided implant surgery is very useful in partially edentulous cases. In fully edentulous cases, however, the absence of teeth makes it necessary to add reference markers. The proposed protocol demonstrates a simple procedure that allows for the superimposition of STL and radiologic data (DICOM format). In the presented patient case, the tissue-bearing area of the prosthesis was relined with a polysulfide impression material and sent to the laboratory. A master cast was produced. The prosthesis was relined to improve intraoral stability and was provided with at least three radiopaque 3D markers. An STL copy of the prosthesis and the model was generated through a laboratory scanner. The patient wore the prosthesis with the attached markers during the 3D radiologic examination. In the planning software (CoDiagnostiX; Dental Wings), the prosthesis markers on the STL were matched to the corresponding markers visible on the DICOM data. Then, the STL of the model was matched to that of the prosthesis. Once the STL of the mucosa and the prosthesis were imported into the software, new possibilities arose, ie, the option to add other digital or traditional tooth setups to the same radiologic data or to design a surgical guide based on the actual mucosa of the patient. Keywords: coDiagnostiX, DICOM, fully edentulous patients, guided surgery, smart fusion, STL