Evaluation of mercury release from dental amalgam after cone beam computed tomography and magnetic resonance imaging with 3.0-T and 1.5-T magnetic field strengths

Abstract

This in vitro study aimed to investigate leakage of mercury from amalgam restorations after cone beam computed tomography (CBCT) and magnetic resonance imaging (MRI) examinations. In total, 238 amalgam disks were prepared and placed in saline solution. The samples were allocated randomly to 7 groups, with 34 samples in each group. CBCT imaging was performed for 4 groups with different imaging parameters (narrow/wide field of view [FOV]; standard/high-resolution). MRI procedures were performed with 3.0-T and 1.5-T magnetic field strengths. No imaging was performed for the samples in the control group. The amalgam samples were removed from the tubes 24 hours after imaging and submitted for plasma mass spectrometry analysis. Kruskal-Wallis and Dunn's tests were performed to compare data. A P value less than .05 was accepted as statistically significant. The highest mean mercury value was found in the 3.0-T MRI group, whereas the lowest mean value was found in the narrow FOV, standard-resolution CBCT group. There were no significant differences between the control group and the experimental groups (P ≥ .338) or between the experimental groups (P > .05). CBCT and MRI procedures similar to those used in patient care caused no significantly different mercury release compared with nonexposed samples.