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

Abstract

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

Materials and methods: CBCT volumes were acquired using the Picasso Trio unit with a Zr implant placed individually in either the anterior or posterior mandibular region, both with and without MAR, under two scanning modes: normal (450 basis images) and high (720 basis images). To measure the SD of gray values, a region of interest was placed mesial to the Zr implant site for artifact assessment. For trabecular bone architecture analysis, a volume of interest was established in the same area. The fractal dimension (FD), connectivity density (ConnD), trabecular thickness (TbTh), and trabecular spacing (TbSp) were calculated.

Results: The Zr implant 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 basis images generally had no impact on SD (P > .05), except in the posterior region without MAR, where the normal scanning mode showed higher SD values (P < .05). Implant presence reduced FD and ConnD in the posterior region; however, this effect was less pronounced with MAR enabled (P < .05). In the control group, the overall high scanning mode reduced FD and ConnD (P < .05), with a minimal effect on TbTh and TbSp (P > .05).

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