Quantitative analysis of dental prostheses materials on the magnitude of artefacts at different positions in cone-beam computed tomography: an ex vivo study

To evaluate the effect of crown materials for fixed prostheses on the image quality at different positions in Cone-Beam Computed Tomography (CBCT). A customized virtual maxillary model with three fixed abutments and six recesses was designed and fabricated using 3D printing. Six cylindrical polypropylene tubes filled with a radiopaque contrast solution (K₂HPO₄) were inserted into the integrated recesses. Three-connected crowns made of zirconia, cobalt–chromium (Co-Cr) alloy, pure titanium, lithium disilicate, and resin were seated and CBCT scanned separately and sequentially. The voxel values of six cylindrical regions of interest from tubes were measured. Mean voxel value (MVV), voxel value inhomogeneity (VVI), and image noise (IN) were calculated. The effect of crown material on MVV, VVI, and IN and the voxel values of the six tubes within each material were compared. Zirconia and Co-Cr had the greatest impact on MVV, VVI, and IN than all other materials, with a greater MVV and VVI for zirconia. Resin had the least impact on MVV, VVI, and IN. The effect of pure titanium and resin did not differ on VVI and IN, and Lithium disilicate and pure titanium did not differ either. The tubes at the ipsilateral side of crowns showed greater spatial heterogeneity than contralateral side in all materials. It is demonstrated that artefact severity is highly material and position-dependent. Zirconia and Co-Cr have the greatest negative impact on CBCT image. Pure titanium and Lithium disilicate have similar inhomogeneity and image noise with resin. All the materials showed the greater negative impact on ipsilateral side than contralateral side. This study provides a theoretical basis for crown material selection and image interpretation from a radiological perspective.