Comparative Analysis of Artifact Expression in Zirconia and Graphene Crowns in CBCT Images From Different Systems

Comparing artifact expression in emerging materials, like zirconia, known for high artifact generation, to lower-density materials like graphene is essential to find ways to minimize it. Evaluating these materials across cone-beam computed tomography (CBCT) systems and acquisition protocols provides a comprehensive performance assessment.

To compare zirconia and graphene-reinforced crowns' volumetric alteration artifact, surface area distortion, and general artifact expression on CBCT images using three systems and three protocols.

An anthropomorphic phantom covered with Mix-D soft tissue-simulator material was scanned using 3 CBCT systems: 3D Accuitomo 170, NewTom VGi evo, and Veraview X800. A single zirconia or graphene crown was placed on the right mandibular second premolar. Three acquisition protocols were used: medium field of view (FOV) with standard resolution (SR), small FOV with SR, and small FOV with high resolution (HR). The CBCT images of the crowns were segmented and analyzed using the 3-matic Medical 17.0 (Materialise) software program to obtain the crown's volume and surface area. The root mean square error (RMSE) between the segmentation results and a reference standard (micro-CT scanning) was used to measure general artifact expression. A two-way repeated measures analysis of variance (ANOVA) was performed to assess the parameters' influence in the volumetric alteration artifact, surface area distortion, and general artifact expression.

The zirconia crown exhibited significantly more volumetric alteration artifact, surface area distortion, and general artifact expression than the graphene crown across all CBCT systems (p < 0.05). For the Veraview X800 system and both materials, the medium FOV protocol showed greater general artifact expression compared with the small FOV with SR protocol (p < 0.05).

Zirconia's greater volumetric alteration, surface detail distortion and loss, and artifact expression in CBCT imaging can be mitigated by using lower-density materials like graphene. Furthermore, optimizing CBCT exposure protocols may independently reduce artifacts and surface distortion, regardless of the material's density.