Abstract
This in vitro study compared the trueness and precision of four contemporary intraoral scanners (IOS) for full-arch implant-supported prostheses in an edentulous maxilla. A high-precision polyurethane master model with four implant analogs and polyetheretherketone (PEEK) scanbodies was fabricated. A reference dataset was obtained using an industrial coordinate measuring machine (CMM). Ten digital impressions were taken with each of the following scanners: PrimeScan, Trios 4, Medit i700, and iTero Element 5D. The datasets were imported into 3D metrology software (Geomagic Control X) to calculate trueness (deviation from the reference scan) and precision (repeatability between scans within the same group) using the root-mean-square (RMS) error. PrimeScan demonstrated the highest trueness (mean RMS: 22.4 ± 3.1 µm) and precision (mean RMS: 14.2 ± 2.5 µm), followed by Trios 4 (trueness: 28.6 ± 4.2 µm; precision: 18.1 ± 3.3 µm) and Medit i700 (trueness: 34.5 ± 5.0 µm; precision: 22.8 ± 4.1 µm). The iTero Element 5D exhibited the lowest trueness (45.2 ± 6.8 µm) and precision (31.4 ± 5.5 µm). Significant differences were observed among all groups (p < 0.05). While all four scanners fell within the clinically acceptable threshold of 150 µm for passive fit, PrimeScan and Trios 4 showed superior dimensional accuracy for edentulous full-arch digital impressions.
