Environmental Aspects of Dental Restorative Materials A review of the Danish situation

摘要

In recent years most Western European countries have adopted regulations aiming at reducing the circulation of heavy metals in the environment. As part of point source reduction strategies the discharge of mercury contaminated wastes from dental clinics has subsequently been regulated e.g. by mandatory installation of amalgam separators. Issues pertaining to the environmental effects of clinical dental practice are scarcely covered in the scientific literature. Environmental authorities in Sweden and Denmark have gone as far as to plan a ban on the use of dental amalgam. Recent national surveys in Scandinavia have shown markedly declining numbers of dental amalgam restorations produced per year. In e.g. Denmark and Sweden a 50-75% decline was thus seen over the last decades. The aim of the present survey is to present data on environmental aspects of dental restorative materials, particularly amalgam, based on the last 10 years Danish experiences on effects of regulatory approaches in relation to the circulation of mercury for dental applications. Results from own studies documenting up to 90% reduction of mercury outlet from dental clinics after installation of amalgam separating devices will be presented. A subsequent national survey showed up to 80% reduction of the mercury load in wastewater treatment plant sludge following regulatory intervention in dental practice. The issue of possible environmental mercury burden in relation to interment/cremation of amalgam bearers is addressed in part by presentation of data from own studies. No mercury could be detected in consecutive season-related drain water samples collected from a cemetery-area which indicates that mercury from dental amalgam is not significantly mobilized from such areas. In conclusion the possible environmental mercury contribution related to the use of dental amalgam can be controlled by adopting adequate routines for mercury hygiene, mercury waste collection, handling and disposal. In both Sweden and Denmark the previously-planned ban of using dental amalgam was recently postponed.