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 exhibited significantly poorer angular trueness compared to the 18 mm and 30 mm (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.