The soft tissue silicone former was removed from the Nissin model to simulate bone anatomy. Subsequently, this model was duplicated with clear resin material mixed with barium sulfate and scanned by a cone beam computed tomography (CBCT) machine to generate cross-sectional DICOM images.

The DICOM images were imported to the implant planning software programs. For the FH protocol, the 2D DICOM images were visualized on a computer screen to decide on the ideal implant position for the anterior and posterior implants. The clinicians had access to the planning images to allow for ideal FH implant placement. For the FG protocol, the DICOM data were imported to coDiagnostiX software (Dental Wings, Montreal, Canada), which is closely related to the implant company, and can design surgical guides that control all steps of implant surgery. For the PG protocol, the DICOM data were viewed in the Blue Sky Bio software (Grayslake, IL, USA), which is an open-source software that is suitable for designing surgical guides for pilot drilling.

For the FG protocol, the virtual cast and the 3D CBCT image were combined by the software, and the virtual intact model was used to simulate ideal teeth replacement. The virtual intact model provided outline of the planned restorations that dictated the implant position. This was followed by placement of virtual implants within the simulated bone in a favorable 3D position. According to the planned implant position, a surgical guide was designed and produced by a commercial dental laboratory by milling through a 5-axis milling unit (DWX-51D, Roland, Sydney, NSW, Australia). Two Straumann metal sleeves of the FG protocol were attached on every guide. The metal sleeves had a 5-mm diameter and were provided by the implant company to accept all the drilling components and the implants. The PG protocol followed similar steps, and the software was used to design surgical guide with pilot drill holes corresponding to the location of the implants. The STL file of the guide was transferred to a 3D printer (ProJet, 3510 DP Pro, 3D systems, Rock Hill, SC, USA) to produce the surgical guides. After printing the guides, two Straumann pilot drilling sleeves (2.2 mm diameter) were inserted. After the virtual implant planning, an STL file of the virtual model with the planned implants was extracted. This model served as a master model to which all the placed implants were compared to.