The Effect of Basis Images and a Metal Artifact Reduction Algorithm on Artifact Expression and Trabecular Bone Architecture in the Vicinity of a Zirconium Dental Implant Placed in Different Mandibular Regions: An Ex Vivo Study.

Abstract

Purpose: To investigate the effect of basis images' number (BI) and metal artifact reduction (MAR) on artifact's expression and trabecular bone architecture assessment in a medullary bone area close to a zirconium implant placed in different mandibular regions on CBCT.

Materials and methods: CBCT volumes were acquired using the Picasso Trio unit with a zirconium implant placed individually in either the anterior or posterior mandibular region, both with and without MAR, under two scanning modes: normal (450 BI) and high (720 BI). To measure the standard deviation (SD) of gray values, a region of interest was placed mesial to the zirconium implant fixture area for artifact's assessment. For trabecular bone architecture analysis, a volume of interest was established in the same area. The fractal dimension (FD), connectivity density (Conn. Dn.), trabecular thickness (Tb. Th.), and trabecular spacing were calculated.

Results: The zirconium implant fixture increased the SD of gray values, especially in the posterior region without MAR, while activating MAR reduced these values regardless of the scanning mode (P < .05). The number of BI generally had no impact on SD (P > .05), except in the posterior region without MAR, where the normal scanning mode showed higher SD (P < .05). Implant presence reduced FD and Conn. Dens. in the posterior region, although this effect was less pronounced with MAR enabled (P < .05). In the control group, overall, high scanning mode reduced FD and Conn. Dens (P < .05), with minimal effect on Tb. Th. and Tb. Sp (P > .05).

Conclusions: The zirconium implant fixture increased artifact expression, particularly in the posterior mandibular region without MAR, which also resulted in decreased FD and Conn. Dens. While increasing the number of basis images had little effect on the parameters, MAR minimized artifact expression and the reductions in FD and Conn. Dens.

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