Digital scan of different intraoral scanners accurate for long-span fixed prosthesis: Study

Five scans were made starting from the right quadrant (ScanR), followed by 5 scans starting from the left quadrant (ScanL). All data sets were obtained in standard tessellation language (STL) file format and were used to evaluate accuracy (trueness and precision) with a 3D analyzing software program (Geomagic Studio 12; 3D Systems) by using a best-fit alignment. The prepared teeth were digitally isolated from the complete-arch and evaluated with the analyzing software program. The Kruskal-Wallis and Mann-Whitney U statistical tests were used to detect differences for trueness and precision (α=.05).

The following results were seen-

1. Statistically significant differences were found regarding IOSs (P<.003) and scanning sequence (P<.05).
2. The TRIOS showed the best trueness for the complete-arch, but not statistically different from Primescan, Virtuo Vivo, and iTero (P>.003).
3. The lowest median values for precision of the complete-arch were also found using TRIOS, but no significant difference was found among the scanners (
   P>.003).
4. In terms of trueness and precision, Primescan had the best accuracy for preparations.
5. Emerald showed significant differences depending on the scanning sequence for complete-arch accuracy.
6. ScanR for trueness (P=.021) and ScanL for precision (P=.004) showed improved results.
7. However, Emerald, TRIOS, and Virtuo Vivo showed statistically significant differences in precision of preparations depending on scanning sequence.
8. ScanL deviated less than ScanR when scanned with TRIOS (P=.025) and Emerald (P=.004), and the opposite with Virtuo Vivo (P=.008).
9. In terms of preparations trueness, no significant difference was found between the ScanR and ScanL of any IOS (P>.05).

Therefore, the authors concluded that "based on this in vitro study, the accuracy of the complete-arch and prepared teeth differed according to the IOS and scanning sequence."