Accuracy of complete-arch digital implant impressions using conventional scanbodies, ScanTransfers, and splinted ScanTransfers: an in vitro study

Abstract

Background: This study aimed to evaluate and compare the accuracy, in terms of trueness and precision, of complete-arch digital implant impressions obtained using various scanbody configurations, and to assess the influence of the scanned arch and intraoral scanner on accuracy. Methods: This study used edentulous maxillary and mandibular resin models with six implants per arch. Three scanbody configurations were evaluated: conventional scanbodies (SB), ScanTransfers (ST), and splinted ScanTransfers (SST). Each configuration was applied to both arches and scanned using two intraoral scanners (3Shape® TRIOS® 4 and Medit® i700 Wireless). Fifteen scans were obtained per subgroup. Reference datasets were acquired using a laboratory scanner. Trueness and precision were quantified as root-mean-square (RMS) deviations after three-dimensional alignment. Statistical analysis included the Kruskal–Wallis H test and Mann–Whitney U test, with Bonferroni correction (α = 0.05). Results: Scanbody configuration significantly influenced both trueness and precision (p < 0.001). The SST group demonstrated the highest trueness (78.54 ± 20.71 μm) and precision (63.40 ± 18.30 μm), while SB and ST showed higher discrepancies. No significant differences were observed between the maxillary and mandibular arches for trueness or precision (p > 0.05), or between scanners (p = 0.198); however, precision was significantly higher with the TRIOS® 4 than with the Medit® i700 Wireless (p = 0.006). All accuracy values fell within previously reported ranges. Conclusions: Scanbody design and splinting influence the reliability of complete-arch digital implant impressions, while arch type appears to have a limited impact. Scanner-related differences may affect reproducibility.