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Updated: Jul 14, 2026
Accuracy in Dental Medicine, A New Way to Measure Trueness and Precision
Published on: April 29, 2014
Influence of three coded healing abutment design on intraoral scan accuracy: a comparative in vitro study
Belén Morón-Conejo1, Ana Federica Stran-Lo Giudice2, María Paz Salido1
1Analysis of Techniques, Material and Instruments applied to Digital Dentistry and CAD/CAM Procedures Research Group, University Complutense of Madrid.
Objective:
To compare the trueness and precision of three coded healing abutment (CHA) systems -Bellatek Encode (BE; ZimVie), iPhysio (IP; Lyra ETK), and Encode Emergence (EE; ZimVie)- for transferring 3D implant position via intraoral digital impressions in vitro.
Methods:
A mandibular epoxy-resin model with four internal‑hex implants at sites 3.5, 3.6, 4.3, and 4.6. served as the reference. Each CHA was torqued to 15 Ncm and scanned in six rotational orientations using an intraoral scanner (Primescan, Dentsply Sirona). STL files were trimmed and divided into anterior and posterior segments. Scans were superimposed on an extraoral reference scan (E4, 3Shape) using a best-fit algorithm in Geomagic. Three-dimensional deviations, 2D axial slices, and angular discrepancies were quantified. Trueness (mean deviations, RMS) and precision (standard deviation) were analyzed. Intergroup comparisons were performed using the Kruskal-Wallis with Mann-Whitney U post hoc tests (α=0.05).
Results:
Group IP exhibited significantly lower 3D mean deviation (49.9 ± 95.4 µm) and RMS (91.5 ± 147.4 µm) than groups BE and EE, and superior precision (72.4 ± 117.5 µm; p < 0.01). In 2D analyses, IP achieved the lowest mean trueness (32.4 ± 87.6 µm) and RMS (76.6 ± 112.5 µm) compared with the other groups (p < 0.01). Segmental analyses revealed greater angular deviations at posterior implant sites, particularly for group EE.
Conclusions:
The IP CHA system demonstrates superior dimensional accuracy and reproducibility compared with BE and EE. Posterior implant position amplify angular deviations, emphasizing the critical role of abutment geometry and implant positioning digital-impression fidelity.
