Evaluation of The Effect of Different Software Parameters and Scanning Methodologies on Digital Impression Accuracy

Background This study aimed to evaluate the accuracy of digital impressions depending on software parameters and different patient scenarios. Methods Five study groups were created by placing implants in two edentulous mandibular and a partially edentulous maxillary epoxy model. In the maxillary model, implants were placed at the central incisor with a 15º angle (Group 1A), first molar with 0º (Group 1P), and first-second molars with 0º (Group 2P). In the first edentulous mandibular model, two straight implants were placed in lateral incisor sites and two 30º angled implants in premolar sites (Group 4). The second mandibular model had six straight implants (Group 6). Models were digitized with a laboratory scanner to obtain reference data. Segmental scans were performed for Groups 1A, 1P, and 2P, while full-arch scans were performed for Groups 4 and 6. Scan depth was adjusted to minimum (12 mm) and maximum (21 mm) settings using intraoral scanner software. The STL data were generated and compared with reference scans to evaluate trueness; precision was assessed by intra-group comparison. One-way ANOVA and Student’s t-test were used (p < .05). Results Minimum scan depth produced less deviation than maximum scan depth in all groups, significantly in full-arch scans (p < .05). Angled implants showed higher deviations. Full-arch scans showed more deviation than segmental scans except in Group 1A. Group 2P had the least deviation for trueness, while Group 4 had the most. For precision, Group 1P had the least and Group 4 the highest deviation. Conclusions Intraoral scanners can be reliably used in various clinical scenarios. Although angled implants did not directly reduce accuracy, higher angulation increased deviations. Minimum scan depth improved accuracy by reducing interference from surrounding tissues. Full-arch scans benefited from more implants and shorter distances between them.