Influence of Artificial Surface Markers on the Accuracy of Full-arch Digital Impressions in Edentulous Arches: An In Vitro Study

Introduction This in vitro study assessed the accuracy of full-arch edentulous impressions obtained via intraoral scanning using various scanning strategies. This study aimed to evaluate whether the addition of surface markers would enhance scan precision in various anatomical regions of edentulous models, particularly on low-feature and smooth surfaces. Methods Sixty scans (30 maxillary and 30 mandibular) were performed using an intraoral scanner across three scanning protocols: unmodified (control), composite-resin, and drawn-line markers. Reference scans were obtained using a laboratory scanner. Scans were evaluated in four anatomical regions: the vestibule, residual ridge, palate/lingual area, and overall surface. Deviations were measured using the root mean square, mean deviation, and standard deviation. Two-way analysis of variance, with Tukey’s post hoc test, was used for the statistical analysis. Results The scanning strategy had no significant effect on the residual ridge area ( p = .918). The jaw type significantly affected the scanning accuracy in all areas ( p < .001), with greater deviations observed in the mandibular scans. Composite-resin and line marker strategies increased the accuracy in the mandibular vestibular and lingual regions. All root mean square error values remained within the clinically acceptable limits, although the numerical differences between the groups were minimal. Conclusion Full-arch intraoral scanning of edentulous models demonstrated clinically acceptable accuracy, within the limitations of this in vitro study. Surface markers did not provide a significant advantage in the maxillary scans but may improve scanning performance in mandibular regions. These findings provide methodological insights into scanning performance on smooth and low-feature surfaces and should be interpreted cautiously when extrapolating to clinical intraoral conditions.