Accuracy of full-arch implant scans using different horizontal scan bodies in an angulated model: An in vitro study

Various newly developed horizontal implant scan bodies have been introduced to enhance full-arch scan accuracy. However, their performance in angulated implant scenarios remains unclear. The purpose of this study was to evaluate the accuracy of four specific horizontal scan body systems.

A stone cast containing six implant abutment analogs served as the master model. Four horizontal scan body systems (ArcB GeoMEDI, Apollo Smartflag, Scan Ladder, and ioConnect) were evaluated. Ten scans were performed per group using an intraoral scanner (Medit i900c). The mean surface deviation, root mean square (RMS) values against the reference files, and the percentage of data points within specific tolerance thresholds were calculated using Geomagic Control X. One-way ANOVA was performed to test the effect of the scan body system on accuracy outcomes (α = 0.05).

Scan Ladder (18.42 ± 2.33 μm) and ioConnect (20.54 ± 3.32 μm) exhibited the highest trueness, significantly outperforming Apollo and ArcB (P < 0.001). Scan Ladder demonstrated the lowest RMS (22.64 ± 2.8 μm), significantly superior to all other groups (P ± 0.011), and achieved the highest concentration of highly accurate data points (<50 μm; 97.47%). While all systems showed good precision, Apollo exhibited the highest rate of extreme deviations (>100 μm; 5.05%).

Scan body design significantly influences full-arch implant scan trueness. Although all systems performed within clinically acceptable thresholds (<31 μm), comprehensive accuracy evaluations should incorporate both RMS values and the distribution of extreme deviations to ensure predictable clinical passive fit.