Effect of the scan body alignment process on the accuracy of virtual definitive implant casts: a pilot study

J Adv Prosthodont. 2025 Oct;17(5):279-291. doi: 10.4047/jap.2025.17.5.279. Epub 2025 Oct 20.

Abstract

Purpose: The aim of the present study was to evaluate whether the accuracy of digital definitive implant casts is affected by both the process of best fit (BF) alignment of the scan bodies (SBs) with the CAD library and the type of scanner used.

Materials and methods: Scans of the upper and lower arches of a totally edentulous patient, each with eight implants, were performed using the Trios-3 (T) and True-Definition (TD) intraoral scanners and the Identica-Light extraoral scanner (EO) for casts. Two types of alignment of the SB with the CAD implant library were performed, using either 3/3 or 1/3 of its mesh. Twelve virtual definitive implant casts were generated, each with a designed prosthetic bar. Analysis included absolute differences in 28 inter-implant distances and 7 relative angles of the bar implant abutments.

Results: Descriptive statistical analysis was carried out, including the calculation of means ± standard deviations and maximum and minimum values for both distances and angles.

Conclusion: In conclusion, the accuracy of digital definitive casts with multiple implants was influenced by both the amount of mesh selected in the SBs during the BF alignment with the CAD library and the optical impression system used.

Keywords: Best fit; Digital workflow; Digital working cast; Implant prostheses; STL mesh; Scan bodies.