Study of mercury release in dental amalgam wearers by measuring salivary and urinary mercury

Abstract

Background. Mercury amalgam remains the most effective and least expensive dental filling material. Mercury is considered by the World Health Organization (WHO) as one of the ten chemicals or groups of chemicals that are extremely concerning for public health. The aim of our study is to assess exposure to mercury from dental amalgams through the measurement of salivary and urinary mercury. Population and methods. This is a prospective, analytical study carried out at the National Toxicology Center of Algiers during the year 2004. The study included 48 subjects with dental amalgams and 12 subjects without amalgams. Mercury levels in saliva and urine were measured by cold vapor atomic absorption spectrometry using the "Flow Inject Mercury System". Results. Compared to other studies, the urinary mercury values in our study are relatively high. This observation is also true for our controls. For salivary values, our subjects have levels (after chewing) that remain within the same range. The comparison of urinary and salivary means shows a significant difference between subjects with three or more amalgams and controls. There is also a significant correlation between the number of fillings and salivary concentrations. Among all amalgam bearers, there is no significant correlation between urinary and salivary concentrations. Elevated levels were noted in our controls compared to foreign studies, indicating probable general exposure (food, atmosphere, etc.). Conclusion. There is a real exposure to mercury from dental amalgams, but is this exposure harmful to the health of the bearers? This risk remains "acceptable" as long as we stay below the accepted limits. It is necessary to protect at-risk groups (pregnant and breastfeeding women, children, and adolescents) from this exposure.