Effect of a metal artifact reduction algorithm on cone-beam computed tomography scans of titanium and zirconia implants within and outside the field of view.

Purpose: This study aimed to evaluate the impact of a metal artifact reduction (MAR) algorithm on cone-beam computed tomography (CBCT) scans of titanium and zirconia implants, both within and outside the field of view (FOV).

Materials and methods: In this in vitro study, a dry human mandible was positioned in a CBCT scanner with only its left quadrant included in the FOV. Each type of implant (titanium and zirconia) was placed once in the right second premolar extraction socket and once in the left second premolar extraction socket of the mandible. CBCT scans were acquired with and without MAR. Three regions of interest (ROIs) were defined in relation to a resin block, and the contrast-to-noise ratio (CNR) was calculated for each ROI. Data were analyzed using 2-way analysis of variance with an alpha level of 0.05.

Results: Application of a MAR algorithm significantly increased the CNR within and outside the FOV for both implant types (P<0.05). Relative to titanium implants, zirconia implants were associated with significantly lower CNRs in both positions (P<0.05) and generated more artifacts. Implant placement outside the FOV was associated with slightly lower image quality than positioning within the FOV, although this finding was not significant (P>0.05).

Conclusion: The results suggest that application of a MAR algorithm in CBCT significantly impacts artifact generation. Titanium implants exhibited significantly lower metal artifact generation compared to zirconia implants. Positioning either implant type outside the FOV, as opposed to inside it, slightly increased artifact generation; however, this was not statistically significant.