Results
The mean±SD age of participants in the control and study groups was 24.4±4.2 and 25.6±3.7 years, respectively (p=0.67). Figure 1 shows the trend of urinary mercury level in the two studied groups. The mean±SD urinary mercury levels before amalgam restoration for the study and control groups were 20.70±17.96 and 20.25±19.77 µg/L, respectively (p=0.87); 72 hrs after amalgam restoration (48 hrs of MRI), the mercury level in the study and control groups were 25.95±21.72 and 18.57±19.04 µg/L, respectively (p=0.038). Later on, 96 hrs of amalgam restoration (72 hrs after MRI), the mercury level in the MRI group was still significantly (p=0.046) higher than that in the control group (p=0.046).