Evaluation of the effect of reducing metal artifacts in multi-detector CT imaging of zirconia and titanium implants.

Objectives: Zirconia oral implants produce larger artifacts on computed tomography (CT) compared to titanium oral implants. This study aimed to compare the effectiveness of metal artifact reduction (MAR) software and dual-energy (DE) methods, which are used in multi-detector CT (MDCT) to reduce the artifacts produced by titanium and zirconia oral implants.

Methods: Oral implants were placed in the lower right second premolar and second molar regions of an acrylic mandible model and evaluated using MDCT. For MAR, Single Energy Metal Artifact Reaction (SEMAR) images were obtained, and for DE, images were obtained at 135 keV. The evaluation was based on 21 regions of interest (ROIs) with sides of 2.8 mm, set at 15, 25, and 35 mm from the center (the lower-right first premolar), with 65°, 90°, 115°, and 145° angles set on the buccal and lingual sides. The evaluation was based on an Artifact Index (AI).

Results: The lingual aspect of the AI tended to be larger compared to the buccal aspect, regardless of the image-processing method. In addition, the SEMAR method tended to have a greater artifact reduction effect than the DE method. The distortion of the mandibular model and occurrence of new artifacts were confirmed using SEMAR.

Conclusions: SEMAR had higher artifact reduction effects on metal artifacts than the DE method. Although SEMAR and dual-energy methods can effectively reduce metal artifacts, they also cause false images and areas that cannot be observed. Therefore, diagnostic and treatment planning, including imaging, is essential before artifact reduction processing.