Effect of voltage and amperage alterations in CBCT on metal artifact generation caused by exomass

Objectives: This study assessed the effect of voltage and amperage alterations in cone-beam computed tomography (CBCT) on metal artifact generation in the exomass. Materials: and Methods: In this in vitro experimental study, titanium dental implants and teeth with cobalt-chromium (Co-Cr) intracanal post, and amalgam build-up restorations were placed in the exomass in a dry human mandible unilaterally and bilaterally. Ballistic gelatin was used for soft tissue simulation. The mandible was scanned by CS8100 3D-Carestream CBCT scanner with 5 x 5 cm field of view (FOV), 60 and 90 kVp voltage, and 2 and 10 mA amperage. The mean gray value (GV) in the region of interest (ROI) at the center of a polypropylene tube containing dipotassium phosphate was calculated on 10 axial sections using OnDemand software. The mean GV and its standard deviation (SD) represented the amount of generated artifacts. Data were analyzed by R software. Results: : Increasing the amperage increased the mean GV and decreased its SD (P<0.05). Increasing the voltage decreased the mean GV and its SD (P<0.05). Metal objects in the exomass significantly decreased the mean GV such that the lowest mean GV and the highest SD was recorded in presence of Co-Cr post followed by titanium implant, and amalgam build-up (P<0.05). Unilateral presence of metal objects had a significantly smaller effect on the mean GV and its SD (P<0.05). Conclusion: Increasing the amperage and voltage decreased metal artifact generation in the exomass. Metal artifacts in the exomass can affect the GV and cause image distortion.