## 4 Discussion  
Based on the results, this study's hypothesis has been confirmed. It was observed that mercury release increases both over time and with a greater number of amalgam-restored teeth. The findings reveal a positive correlation between the concentration of mercury in artificial saliva and the duration of amalgam aging, persisting for up to 30 days. Our results substantiate a consistent upward trend in mercury levels within the artificial saliva over the 30-day period following amalgam placement. Prolonged exposure of amalgam surfaces to the artificial saliva medium leads to a marked elevation in the mercury concentration, highlighting the temporal dynamics of mercury release in such conditions. In this study, cavity preparations were designed to replicate clinical conditions, and an in vitro setup was deliberately chosen to yield clinically relevant outcomes. Mercury release was comparatively evaluated at various time intervals from teeth with differing surface areas and quantities. Plastic model teeth were employed instead of natural human teeth to ensure standardization, as it is not feasible to determine the extent of mercury exposure a natural tooth may have undergone prior to extraction. The use of plastic teeth also served to eliminate potential variability between the experimental groups. Mercury occurs in multiple forms: organic mercury, in which mercury is chemically bound to a carbon-containing structure (e.g., methylmercury, ethylmercury, phenylmercury, and others), and inorganic mercury, which encompasses metallic mercury and mercury vapor (Hg\({}^{0}\)), along with mercuous (Hg\({}^{+}\)) and mercuric (Hg\({}^{2+}\)) salts. The toxicity and absorption of mercury are dependent on its chemical form. Due to the instability of the mixing compound, mercury vapor (Hg\({}^{0}\)) is emitted from dental amalgam over time into the air of the oral cavity and is readily absorbed through the lungs [26]. All forms of  
Figure 2: The line graph representation of mercury emission values for each group at each interval. mercury are neurotoxic depending on the dose, but even at low levels, Hg\({}^{0}\) is known to be both neurotoxic and nephrotoxic [21; 30]. Researchers agree that mercury is released from amalgam restorations into the oral cavity [4; 22; 30; 44; 45]. The chemical system formed by saliva and amalgam is particularly complex. The daily mercury absorption from amalgam fillings ranges from 9 to 17 \(\upmu\)g, with an estimated uptake of 12 \(\upmu\)g per day [26]. The lowest dose of mercury that can trigger a toxic reaction is reported to be between 3 and 7 \(\upmu\)g per kilogram of body weight [46]. Mercury is omnipresent in the environment, present in various foods, air, paint, and certain pharmaceuticals. The contribution of dental amalgam to an individual's total daily mercury exposure is regarded as relatively minor. Initial estimations of the average daily intake in individuals without occupational exposure ranged between 1.24 and 27 \(\upmu\)g per day [47; 48; 49; 50; 51; 52]. However, more recent research suggests that the daily mercury dose derived from amalgam is lower than previously reported [29; 52; 53; 54]. Conversely, one study reported that individuals with more than 12 occlusal amalgam surfaces exhibit mercury concentrations in the pituitary gland and cerebral cortex that are tenfold higher than those observed in individuals with three or fewer occlusal amalgams [55]. The average discrepancy in hectogram urine (HgU) levels between the amalgam-free cohort and those with a substantial number of amalgam restorations was 24 nmol/L (4.8 \(\upmu\)g/L).