Effect of shape and size of implant scan body on scanning accuracy: An in vitro study.

Objectives: Evaluating the effect of shape and size of implant scan body on the accuracy of optical 3D scanning.
Materials and Methods: Fifteen PEEK scan bodies were milled, including 1 spherical, 9 cylindrical, and 5 cuboidal. The 3D position and angulation of each scan body were measured using a CMM 3 times and a laboratory scanner 10 times. The linear and angular trueness and precision of the scans were calculated by comparing with the CMM measurements.
Results: The linear accuracy of the cylindrical scan bodies (9.5 ± 6.2 µm) was significantly higher than those of the cuboidal (17.7 ± 8.1 µm) and spherical scan bodies (12.5 ± 6.5 µm). The cuboidal (0.050±0.009°) showed significantly better angular accuracy than the cylindrical (0.065±0.040°). In the cylindrical group, the narrow (∅4.8 mm) demonstrated significantly inferior accuracy than the wider (∅5.5 mm and ∅6.5 mm)(p = 0.003). The tall (12 mm) showed significantly higher angular trueness than the shorter (8 and 4 mm)(p < 0.001). In the cuboidal group, the 24 mm ² exhibited significantly poorer angular trueness compared to the 18 mm ² and 30 mm ² (p < 0.001) CONCLUSIONS: The shape and size of the implant scan body significantly affect the scanning accuracy. Spherical scan bodies cannot transfer implant angulation. Scan bodies with a size of >∅4.8 mm and >8 mm seem accurate for transferring the 3D implant position.
Clinical Significance: The shape and size of scan bodies directly influence the accuracy of 3D scanning. Well-designed scan bodies offer better transfer results, which is crucial for ensuring passive fit of implant prostheses and improving long-term clinical outcomes.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
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