Dimensional Accuracy of Close Tray vs. Digital Techniques in Implant Impressions– An in vitro study

Background: Precise dimensional impression accuracy is crucial in dental prosthetics and implantology. This study aims to compare the dimensional accuracy of implant impressions achieved through intraoral scanning and conventional impression methods for parallel and angled implants. Materials: This study created a partial edentulous maxillary model using heat-cured acrylic, with four fixtures in the premolar areas and two posterior implants inclined 15 degrees lingually on each side. Close tray copings and intraoral scanning with a TRIOS scanner were used for impressions. Distances A1, A2, and A3 (the distance between the most superior point of the central axis of two parallel implants, one parallel, and one angled implant, and two parallel implants, respectively) on the casts were measured using a Coordinate Measuring Machine (CMM). Data were analyzed using Statistical Package for the Social Sciences SPSS, with a significance set at P < .05, and T-tests were conducted. Results: The digital method demonstrated statistically significant higher accuracy in the A1 and A3 distances (p-value=0.042 and 0.046, respectively). However, no significant difference was observed in the A2 distance (P = 0.205). Conclusion: Digital methods proved more effective for transferring implant positions and creating related prosthetics, particularly in cases with notable implant angle variations. Nonetheless, both digital and conventional methods are clinically acceptable for implant position transfer.