Purpose: To evaluate the effect of cheek retractors on the accuracy of capturing peripheral borders in totally edentulous digital scans by comparing the conventional impression technique to digital scans made using two different cheek retractors. Materials and Methods: In total, 16 edentulous maxillary impressions were made using three techniques: (1) the conventional impression technique, using modeling thermoplastic compound and zinc oxide eugenol paste; (2) the digital intraoral scanning technique, using the DIO scan retractor (DIO); and (3) the digital intraoral scanning technique, using the Brånemark lip retractor (BRAN). The control impressions of each patient were poured, scanned using a desktop scanner, and transferred into a 3D-analysis software. DIO and BRAN groups were scanned using an intraoral scanner, imported, and superimposed, using best-fit algorithm on the corresponding control. The root mean square for the whole surface and for particular regions of interest were calculated to assess the degree of trueness. Patient perception of the impression techniques was the secondary outcome. Statistical analyses were performed using one-sample t test and Wilcoxon test (α = .05). Results: Significant discrepancies were found for BRAN and DIO compared to the control. No significant discrepancies were found when comparing RMS of BRAN and DIO at different regions. Scan retractors had a significant impact on patient satisfaction, with patients preferring DIO. Conclusions: Edentulous intraoral scans made using cheek retractors had similar deviations when compared to each other but diverged from the conventional impression in the edentulous maxilla. Patient preference for intraoral scans over conventional impressions was confirmed. The use of different retraction methods during intraoral scanning of totally edentulous maxillary arches does not affect the peripheral border registration.
