## 2 Materials and Methods
The DICOM data acquired from CBCT were converted to STL format through a specialized 3D mesh processing software system (Planneca Romerxis version 6.2, Helsinki, Finland), which can be used in most CAD software (Planneca Romerxis version 6.2, Planmeca Oy, Helsinki, Finland; available at: [[https://www.planmeca.com/dental-software/romexis-viewer/](https://www.planmeca.com/dental-software/romexis-viewer/)]([https://www.planmeca.com/dental-software/romexis-viewer/](https://www.planmeca.com/dental-software/romexis-viewer/)), [[https://www.planmeca.com/dental-software/downloads/](https://www.planmeca.com/dental-software/downloads/)]([https://www.planmeca.com/dental-software/downloads/](https://www.planmeca.com/dental-software/downloads/)), accessed on 20 February 2024). The 3D STL images obtained from the intraoral scanner, laboratory scanner, and CBCT scans were transferred to a CAD software (Cerecc CAD System, Sirona Dental Systems GmbH, Bensheim, Germany), and CBCT unit (Planneca Promax 3D Max Machine, Helsinki, Finland). CBCT scans were performed 0.075 mm voxel size. In order to standardize the imaging technique, all scans were taken at 90 kVp, 12 mA, and 50 mm \(\times\) 40 mm FOV size. Prior to the main study, all scanning devices were calibrated and checked according to the manufacturers' guidelines. The intraoral scanner (CEREC Omnicam; Sirona Dental Systems GmbH, Bensheim, Germany), model scanner (inEOS X5; Sirona Dental Systems GmbH, Bensheim, Germany), and CBCT unit (Planneca Promax 3D Max; Planneca Oy, Helsinki, Finland), and CBCT unit (Planneca Promax 3D Max; Planneca Oy, Helsinki, Finland) underwent routine quality control, including internal calibration and software-based diagnostic checks. In addition, test scans were performed to ensure consistent output and proper device performance before data collection. The DICOM data acquired from CBCT were converted to STL format through a specialized 3D mesh processing software system (Planneca Romerxis version 6.2, Helsinki, Finland), which can be used in most CAD software (Planneca Romerxis version 6.2, Planmeca Oy, Helsinki, Finland; available at: [[https://www.planmeca.com/dental-software/romexis-viewer/](https://www.planmeca.com/dental-software/romexis-viewer/)]([https://www.planmeca.com/dental-software/romexis-viewer/](https://www.planmeca.com/dental-software/romexis-viewer/)), [[https://www.planmeca.com/dental-software/downloads/](https://www.planmeca.com/dental-software/downloads/)]([https://www.planmeca.com/dental-software/downloads/](https://www.planmeca.com/dental-software/downloads/)), accessed on 20 February 2024). The 3D STL images obtained from the intraoral scanner, laboratory scanner, and CBCT scans were transferred to a CAD software (Cerecc CAD System, Sirona Dental Systems GmbH, Bensheim, Germany), and CBCT unit (Planneca Promax 3D Max Machine, Helsinki, Finland). CBCT scans were performed 0.075 mm voxel size. In order to standardize the imaging technique, all scans were taken at 90 kVp, 12 mA, and 50 mm \(\times\) 40 mm FOV size. Prior to the main study, all scanning devices were calibrated and checked according to the manufacturers' guidelines. The intraoral scanner (CEREC Omnicam; Sirona Dental Systems GmbH, Bensheim, Germany), model scanner (inEOS X5; Sirona Dental Systems GmbH, Bensheim, Germany), and CBCT unit (Planneca Promax 3D Max; Planneca Oy, Helsinki, Finland) underwent routine quality control, including internal calibration and software-based diagnostic checks. In addition, test scans were performedGmbH, Bensheim, Germany), and inlay restorations for mandibular molars were designed. No manual corrections were made during the design phase except for minor corrections in the margin drawing to avoid operator-related errors. The cement space was set to 20 \(\upmu\)m in the marginal area and 80 \(\upmu\)m in the remaining areas inside the inlay restoration.