Relationship between the number of tooth surfaces restored with amalgam and mother's breast milk mercury levels: A preliminary study

Mother's milk is very suitable for the nourishment of infants. Despite the capability of breast glands to refine and purify, some poisonous metals, such as mercury, might seep into the mother's milk. The aim of this study was to determine the relationship between the number of tooth surfaces restored with amalgam and the amount of mercury in mother's milk because mercury is one of the constituents of dental amalgam. In this preliminary descriptive study the subjects consisted of breast-feeding mothers referring to a health center in Isfahan. A total of 25 systemically healthy mothers, aged 18-35, who had given birth less than two months previously, were selected. Simultaneously, 5 mothers with no amalgam restorations were selected as the control group. At first the number of tooth surfaces restored with amalgam was recorded. Then approximately 6 mL of milk were taken from each mother. The mercury levels of the milk samples were measured by cold vapor atomic absorption spectrophotometric method. Data were analyzed by SPSS using independent t-test and correlation coefficient. The average number of amalgam surfaces restored in 25 samples in the test group was 14.56. The mean of milk mercury level was 1.5748. There was a significant relationship between mercury levels of mothers’ milk and the number of amalgam restoration surfaces (p value < 0.001). Under the limitations of this study there was a significant relationship between mercury levels of mothers’ milk and the number of amalgam restoration surfaces.