Complete arch digital implant scans in the edentulous maxilla: Trueness and time efficiency based on scan body height, splinting, location, and scanner system.

STATEMENT OF PROBLEM: Accurate digital scans of edentulous arches remain challenging. Combined effects of scan body height, splinting, location, and scanner on complete arch implant trueness have not been clarified.

PURPOSE: The purpose of this in vitro study was to evaluate scan body height, splinting, implant location (anterior/posterior), and 3 intraoral scanners on the trueness of 6-implant edentulous maxillary scans.

MATERIAL AND

METHODS

Polyetheretherketone (PEEK) scan bodies with cylindrical geometry and 3 different heights (4.5 mm, 6 mm, 8 mm) were tightened on straight mini-unit abutments on 6 Morse implants in a 3-dimensionally (3D) printed resin model. Scans were performed splinted and nonsplinted using 3 different intraoral scanners (PrimeScan [PS]; TRIOS 5 [TR]; Infinite [IF]). Deviations at implant locations were quantified in micrometers. Trueness analysis was measured by overlaying scans in the Geomagic X Design software program. Deviations were quantified by root mean square (RMS) values. Statistical analysis was performed in Jamovi (v.2.3), including normality assessment (Shapiro-Wilk) and nonparametric comparisons using the Kruskal-Wallis and Mann-Whitney U tests with Dwass, Steel, Critchlow-Fligner (DSCF) Multiple Comparisons tests (α=.05).

RESULTS

Scan body height significantly affected trueness in all scanner groups (P<.001). The highest implant scan trueness was obtained with a 4.5-mm scan body height using the TR scanner (P<.001), and the lowest trueness was seen with an 8-mm scan body height and IF scanner (P<.001). Splinting did not affect the trueness for 4.5-mm scan bodies (P=.392) but significantly improved scan trueness for 6-mm and 8-mm scan bodies (P<.001). Regarding scanning time, splinting reduced the mean time for 6-mm scan bodies with both TR (P=.005) and PS scanners (P=.002) and for 8-mm scan bodies with IF (P=.016. Within the location, scanner height had a significant effect on trueness (P<.001).

CONCLUSIONS

Scan body height and scanner type significantly affected the trueness of complete arch scans. The 4.5-mm scan bodies demonstrated the best trueness across scanners. Although splinting did not improve trueness, it contributed to reduced scanning time for taller scan bodies (6- and 8-mm). Short scan bodies (4.5 mm) enabled higher trueness in the posterior region, while intermediate height (6 mm) led to higher trueness in the anterior region.