Intraoral scanning devices are an essential part of many digital pathways in dentistry. The aim of this first factorial comparative in-vitro study was to evaluate the influence of different jaw model configurations (model types: upper jaw upper, upper jaw with palate upper-pal, lower jaw lower) and examiners on trueness and precision of digital full-arch impressions across seven intraoral scanners. Reference models were scanned with Emerald Green EME; iTero 5D ITE; Medit i900 MED; Primescan PRI; Primescan2 PS2; Aoralscan 3 SHI; Trios 5 TR5. Each model type was scanned ten times (n = 10) per device, divided between two examiners with different experience levels. Trueness and precision were calculated using the (90₁0) /2-percentile. Data were analyzed using a linear mixed-effects model with model type and examiner as fixed effects and scanning device as a random effect. The trueness values ranged from PRI (29. 0 ± 3. 7 μm, upper-pal) to EME (94. 9 ± 18. 5 μm, lower). Examiner and model type had no significant effect on trueness. For precision, the model type upper-pal showed a significant positive effect (p < 0. 001), factor examiner had a significant effect (p = 0. 04). The model type and examiner experience can influence the accuracy of digital impressions; however, the values observed were within clinically acceptable thresholds (< 100 μm). Including the palate in upper jaw scans can improve accuracy for certain intraoral scanners. Optimizing scanning strategies, exercising and considering jaw anatomy-especially the inclusion of the palate-may enhance scanners' accuracy.
Buhl et al. (Thu,) studied this question.