Comparative in vitro evaluation of trueness and precision in five intraoral scanners across multiple clinical scenarios

Objectives: With rapid technological advancements, numerous intraoral scanners (IOS) are available. This study evaluates and compares the trueness and precision of five IOS across four clinical scenarios to provide benchmark comparative data. Resin models included a completely edentulous maxilla, a dentulous maxilla, a lower jaw with 10 prepared teeth, and an edentulous mandible with six implant scanbodies. Methods: Reference scans were obtained using a high-resolution extraoral scanner. Each model was scanned 10 times with five IOS (Aoralscan 3, CS 3600, iTero Element 5D, TRIOS3, Virtuo Vivo). 3D stereolithography files were created, and IOS scans were compared to reference scans using reverse engineering software. NURBS/NURBS scanbody library file comparison was performed on implant models. Statistical analysis (SPSS 26) assessed trueness and precision (root mean square values), using ANOVA and post-hoc tests (p < 0.05). Results: TRIOS3 had the best trueness in all groups except group D (iTero: 22.6 ± 2.4 μm). TRIOS3 also showed the best precision across all groups (e.g., group D: 14.5 ± 7.6 μm). Significant differences were found between IOS and between groups using the same IOS (p < 0.05). ICC tests indicated excellent correlation, and Dahlberg's formula confirmed minimal method error. Conclusions: Within the limitations of this in vitro study, TRIOS3 and iTero Element 5D demonstrated higher trueness and precision among the tested devices. These findings should be regarded as reference benchmarks, and future studies should validate them in vivo while assessing next-generation IOS. Clinical significance: This study provides methodological benchmark data on older-generation IOS models. While TRIOS3 and iTero Element 5D performed better than other devices tested, clinical translation requires caution, and newer scanners must be evaluated in future studies.