Congruence between the meshes of a combined healing abutment-scan body system acquired with four different intraoral scanners and the corresponding library file: an in vitro analysis

Abstract

Objectives: To investigate the congruence between the meshes of a combined healing abutment-scan body (CHA-SB) system acquired with four different intraoral scanners and the corresponding library file. Material and methods: A CHA-SB was fixed to an implant at the right first molar position in a dentate mandibular model and digitized by using 4 different intraoral scanners (IOSs) [TRIOS 3 (T3), Omnicam (OC), Primescan (PS), and Virtuo Vivo (VV)] (n = 8) and an industrial grade optical scanner (ATOS Core 80) (n = 1) to generate standard tessellation language (STL) files of the test scans (CHA-SB-STLs) and the master reference model scan (MRM-STL). A reverse engineering software (Studio Geomagic X) was used to superimpose the proprietary library file of the CHA-SB over the generated STL files. Root mean square (RMS) values representing the deviations between the library file and the superimposed STL files were statistically analyzed by using 1-way ANOVA (α=0.05). Qualitative analysis of the deviations was performed by visual inspection. Results: Differences between the congruence of the library file and the CHA-SB scans among different IOSs were nonsignificant (F = 1.619, df= 3, P = .207). The single best result was 29 ± 28.9 µm for OC, 30.8 ± 29.6 µm for VV, 35.6 ± 35.5 µm for T3, and 39.5 ± 39.2 µm for PS, which were all above the deviation value of the scan performed by using the industrial-grade scanner (23.2 ± 23.2 µm). Conclusion: The dimensional congruence between the library file and the STL file of the CHA-SB system scans was similar when intraoral scanners with different acquisition technologies were used to scan a model with an implant. Clinical significance: Scans of the tested intraoral scanners may result in crowns with similar positional accuracy, given the similarities in congruence of their scans with the library file.