Comparing Scanning Accuracy of Full-Arch Maxillary Implants: Extraoral vs. Intraoral Techniques

Data acquisition from the patients: After 4 months of implant placement, three impressions/scans will be made for each patient as follows: Data 1: conventional impression using open tray transfer copings and silicon impression material. After cast verification, the scan bodies will be connected to the analogues on the master cast, which will be scanned using a laboratory scanner. The STL file will be used as a reference scan. Data 2: The scan bodies will be connected to the implants intraorally, and an intraoral scan will be made using the intraoral scanner. The STL file will be stored for comparison. Data 3: the scan bodies will be splinted using dental floss after being connected to the implants intraorally and then a scan will be made using the intraoral scanner. The STL file will be stored for comparison. \- Data alignment and accuracy measurements: The accuracy measurement will be done based on ISO 5725 in which a combination of trueness and precision was approved to define the accuracy of the measurement method. (15) The scanned data will be compared as follows: the STL files from the intraoral digital scans (data 2 and 3) and the extraoral scan of the master cast (data 1) will be imported into a 3D inspection software program that is a metrology program used to analyse and compare 3D meshes. The information for both reference and targets (the scanned data to be compared) will be uploaded into the program and the area of interest of 3D meshes will be marked, The "3D Compare" function will be employed by projecting all paired points with a colour-coded map created to display the deviation patterns of the investigated surfaces. The superimpositions will be used to assess the 3D accuracy for both the digital intraoral scans with the extraoral scan of the verified stone casts. \- Statistical analysis: Data will be collected, analysed, and then tabulated.