Accuracy assessment of prototypes produced using multi-slice and cone-beam computed tomography

The objective of this study was to assess and quantify the dimensional error of prototypes produced using multi-slice and cone-beam computed tomography (MSCT and CBCT). Titanium screws were inserted into a dry skull at different points of the midface. The skull was scanned using MSCT (LightSpeed16) with pixel size 0.3 mm and CBCT (i-CAT Cone-Beam 3D) with voxel sizes 0.25 and 0.4 mm. Prototypes were printed (fabricated) using a ZPrinter 310 device. Both the dry skull (gold standard) and the prototypes were measured using a Mitutoyo 3D coordinate measuring system with three perpendicular axes (X, Y, and Z). The prototype produced from MSCT data presented a mean dimensional error of 0.62%; the two models produced with CBCT images yielded errors of 0.74% with voxel size 0.25 mm and 0.82% with voxel size 0.40 mm. No significant differences in dimensional errors were observed across the prototypes (p=0.767; Friedman's non-parametric test). Prototypes produced from CBCT data using voxel sizes of 0.25 and 0.4mm, and also the one produced from MSCT data using pixel size 0.3mm, showed acceptable dimensional errors and can therefore be used in the fabrication of prototypes in dentistry.