Comparison of 3D extraoral scanning of artex articulator scan vs scan fixator in a fully edentulous arch – in-vitro study

BACKGROUND: This in vitro study compared the precision of articulator-based scanning and scan fixator-based scanning in completely edentulous arches with implant scan bodies. MATERIALS AND METHODS: Upper and lower master casts were fabricated from a typodont, and six implant replicas were placed in each arch. Final impressions were used to fabricate master casts, which were subsequently mounted on an Artex articulator. Implant scan bodies were attached during the digital scanning procedures. Two scanning protocols were evaluated: (1) casts mounted on an Artex articulator and (2) casts mounted using a scan fixator. Each configuration was scanned ten times using an extraoral desktop scanner, and all scans were exported as STL files. Precision was evaluated using CloudCompare software by performing pairwise superimpositions within each group. Root mean square (RMS) values were calculated from all pairwise comparisons to assess intra-group variability. RESULTS: A total of 45 pairwise comparisons per group were analyzed. RMS values showed high variability and right-skewed distributions. The scan fixator showed a mean RMS of 106.6 ± 206.8 μm (median 17.9 μm), while the articulator showed 178.9 ± 276.5 μm (median 22.2 μm). No significant difference was found between groups using the Wilcoxon signed-rank test (p = .446) or the paired t-test on log-transformed data (p = .334). After excluding 20 outlier pairs, results remained unchanged (p > .4 for both tests). Overall, both systems demonstrated comparable precision with no statistically significant differences in RMS values. CONCLUSION: There was no statistically significant difference in precision between articulator-based scanning and scan fixator-based scanning in edentulous arches with implant scan bodies. The scan fixator may represent a cost-effective and clinically acceptable alternative in digital implant workflows.