Effects of X-rays and magnetic resonance imaging on mercury release from dental amalgam into artificial saliva

We have investigated the effects of X-rays and magnetic resonance imaging (MRI) on the release of mercury from dental amalgam into artificial saliva. A commercial brand of amalgam capsules was used, and the capsules were molded into discs (diameter 3 mm, thickness 1 mm) in plexiglas molds before treatment. The samples were divided into three groups. The first group was exposed to X-rays, the second group was exposed to MRI in a soft tissue-equivalent material, and the third group contained an equal number of samples as a control group. All samples were stored in artificial saliva for 1, 2, or 24 h. Mercury analyses were performed with a cold vapor atomic absorption spectrometer. The results were analyzed by two-way repeated-measures analysis of variance with the Bonferroni correction as a post hoc test at the 95 % confidence level. A significant increase in mercury was detected in the X-ray-exposed group versus the control group (mean values 5.79 vs. 3.84 ppb, respectively; p a parts per thousand currency sign 0.05). However, no significant difference in mercury dissolution was found between the MRI-exposed group and the control group (mean values: 4.51 vs. 4.30 ppb). Mercury release increased after exposure to X-rays, but no change was detected after exposure to MRI.