Comparison of Conventional and Digital Intraoral Scanning Method of Obtaining Complete Arch Dental Impressions.

Abstract

Purpose: To compare the accuracy of digital and conventional complete-arch impressions in a clinical setting.

Materials and methods: An in-vitro study was first conducted using a full-arch maxillary Nissin Typodont reference model. Three intraoral scanners Dentsply Sirona CEREC Primescan AC, Straumann Virtuo Vivo, and 3Shape TRIOS 3 were compared against conventional vinyl polysiloxane (VPS) impressions. Stereolithography (.stl) files were analyzed using Exocad DentalCAD software, employing Best Fit Alignment and Cut View Analysis at three key regions:• Cusp of maxillary right canine• Palatal cusp of maxillary left second premolar• Mesiobuccal cusp of maxillary right first molar. A secondary clinical evaluation involved 8 participants, each contributing three digital scans and one conventional VPS impression, resulting in a total of 32 samples (4 per participant). All STL files were analyzed using the same protocol. Statistical tests included one-way ANOVA and post hoc Tukey test (P < 0.05).

Results: In clinical analysis, Virtuo Vivo showed the lowest discrepancy at the maxillary right canine (0.042 ± 0.015 mm), and TRIOS 3 the highest (0.061 ± 0.020 mm) (P = 0.394). At the left second premolar, TRIOS 3 had the lowest (0.039 ± 0.014 mm) and Primescan the highest (0.059 ± 0.021 mm) (P = 0.790). For the right first molar, Primescan showed the least discrepancy (0.047 ± 0.016 mm) and Virtuo Vivo the highest (0.063 ± 0.022 mm) (P = 0.330). Differences were not statistically significant; digital impressions were comparable in accuracy to conventional methods.

Conclusions: Digital impressions are a reliable alternative to conventional impressions, with minimal differences in accuracy. Regional variation highlights the importance of technique and scanner-specific optimization. Ongoing advancements in intraoral scanning technology continue to improve clinical precision.