The effect of magnetic resonance imaging on mercury release from dental amalgam at 3T and 7T

Abstract

Overview

This study aims to evaluate the impact of magnetic resonance imaging (MRI) on the release of mercury from dental amalgam under different conditions.

Objectives

• To measure mercury release from standardized constructs composed of hydroxyapatite/amalgam during MRI.
• To investigate the effects of static MRI field strength and radiofrequency (RF) power on mercury release.

Methods

Amalgam was fused into 140 hydroxyapatite disks and matured for 14 days in artificial saliva. Before MRI scanning, disks were divided into five groups, with varied exposure to 3T and 7T MRI field strengths at high and low RF power. Mercury concentrations were measured using inductively coupled plasma mass spectrometry, and statistical analysis involved one-way and two-way ANOVA.

Findings

The study highlighted an increase in mercury levels in groups exposed to 7T MRI and the 3T high RF power MRI compared to the control group. Notably, MRI field strength and RF power significantly influenced mercury release. However, the amount of mercury released during one 3T MRI scan remains substantially lower than the weekly intake considered safe.

Conclusion

Although there is a measurable increase in mercury release from dental amalgam during MRI scans, it is important to note the amount released is relatively small. The findings suggest potential health implications but affirm that mercury remains below hazardous levels during typical MRI exposure.