Cherukara, GeorgeAlghafes, Mohammed2025-03-182023-11https://hdl.handle.net/20.500.14154/75061Background: Several studies have attempted to compare intraoral scanning versus conventional impression methods. However, only a few studies have delved into the impact of diverse types of impressions 'in reproducing the finish line preparation. This in-vitro study aims to compare the reproducibility of the proximal width of the finish line from a 3D printed model with conventional, direct, digital and indirect digital impressions.Material and methods: 3D models were designed using Autodesk Fusion 360 software(Education License) and printed using Asiga printer MAX(Asiga, Alexandria NSW 2015, Australia), incorporating 32 prepared teeth in upper and lower jaws. Three Conventional impressions using (PVS) were made, and three direct digital scanning of the 3D-printed model was performed. Additionally, three indirect digital scanning using 3Shape D800 scanner (3Shape A/S Holmens Kanal7 1060 Copenhagen Denmark) of the conventional impression was conducted. The resulting data were meticulously analysed using Autodesk Fusion 360 software.Results:Statistical analysis shows high intra-rater reliability, while interrater reliability shows low intraclass correlation between different measurement groups of finish line width measurements based on the technique employed, anatomical location and materials used. Direct digital impressions exhibited superior accuracy and reliability, showcasing their potential transformative impact on clinical dentistry. In contrast, indirect digital impressions demonstrated decreased accuracy in measuring finish line width. Conclusion:This study underscores the crucial influence of impression techniques on capturing the proximal width of the finish line. Direct digital methods emerged as the most precise and reliable, offering revolutionary possibilities for dental practice. The findings emphasize the importance of careful technique selection, practitioner proficiency, and material quality in achieving optimal clinical outcomes in dental impressions.62enDigitalconventional Impression3d printersThesis