The purpose of this study was to compare the accuracy of three complete-arch implant scan strategies.

(1) Multi-unit abutment scanbody (SRA 4.6mm scanbody; Straumann), (2) Non-symmetrical shape scanbody (EXACT™ scanbody; Straumann), and (3) Non-symmetrical shape scanbody with scan aids bonded with resin (EXACT™ scanbody and LINKs; Straumann).

Result:

Based on the 3D deviation maps, the non-symmetrical scanbody with the scan aids showed the greatest deviations compared to the reference scan, as indicated by more prominent red/blue regions. In contrast, the non-symmetrical scanbody demonstrated the least deviation, as shown in green. The multi-unit scanbody showed an intermediate deviation pattern. At the ±100 µm, deviations were most evident in the regions around the implant connection/intaglio cylinder, whereas the remaining prosthesis body generally appeared stable.

Conclusion: 

All three IOS strategies showed similar deviation patterns relative to the control group. In this pilot study, the non-symmetrical scanbody appeared comparable to the control group, while adding scan aids did not improve trueness and may have introduced error by partially obstructing the scanner during image capture. Additional studies with a larger number of repeated scans are required to confirm these findings.