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

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. 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). 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. 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.