A group of women after delivery and lactating mothers was examined in the years 1993-1997 which were dentally treated during pregnancy or early motherhood. All individuals were dentally examined, interviewed for occupational and food load of mercury and samples of urine and breast milk were analysed for mercury levels. Filling of teeth when necessary were provided by composite and glassionomer filling materials. In 24 patients there was necessary to grind out old and damaged amalgam fillings while in other n 8 patients only primarily decayed teeth had to be treated. In a group of lactating mothers with the dental anamnesis in pregnancy with manipulations with amalgam fillings there were significantly elevated mercury levels in urine but not in the samples of breast milk when compared with those without manipulations with amalgam in the mouth during pregnancy.

        Key words: mercury – urine – breast milk – amalgam filling – dental treatment in pregnancy