The real cost of dental mercury

Executive summary

While its use has essentially been eliminated in many countries, dental amalgam is now being considered for a global phase-out in the ongoing mercury treaty negotiations^[1] and in the European Union (BIO 2012) because of significant environmental concerns.  The negative effects of mercury releases related to amalgam use are widely recognized in countries where its use has been prevalent: it is often the largest source of mercury in municipal wastewater as well as an increasing source of mercury air pollution from crematoria.  On the other hand, high-quality mercury-free alternatives have long been available.  While most dental professionals charge lower prices for amalgam fillings than for mercury-free alternatives, this paper shows that when factoring in “external” environmental and societal costs,[2] amalgam is a higher-priced dental material by far (Hylander and Goodsite 2006).  Ultimately, society pays for mercury releases related to amalgam use through additional pollution control costs, the loss of common (public-owned) resources, and the health effects associated with mercury releases and contamination (MPP 2008).

According to the United Nations Environment Programme, the use of mercury in tooth fillings represents some 10% of global mercury consumption, thus being among the largest consumer uses of mercury in the world (AMAP/UNEP 2008).  In the U.S., as demonstrated in this report, mercury use in dentistry amounts to over 32 tons^[3] annually, which is considerably more than some recent estimates.^[4]  For comparison, in the European Union dental applications comprise the second largest use of mercury, amounting to some 20-25% of the annual consumption of mercury in the EU.  With something less than twice the population of the U.S., the EU use of mercury in dentistry is somewhat more than twice the U.S. consumption (BIO 2012).

Although the relative health risks due to direct human mercury exposure from amalgams are still being debated, the significant releases to the environment of dental mercury in waste and through other pathways, as well as its persistence once it reaches the environment, are well established:

·       to the soil via wastewater sludge to land disposal, burial of deceased persons with fillings, atmospheric deposition following cremation or wastewater sludge incineration, etc.,

·       to the atmosphere via cremation, etc.,^[5]

·       to surface waters, and

·       eventually to the groundwater.

With a specific focus on the situation of the United States, this report demonstrates that the basic cost to the patient of an “equivalent” amalgam filling in the U.S is $144 compared to $185 for an “equivalent” composite filling.  However, the report then demonstrates that when the real cost (to the environment and society at large) of amalgam is accounted for, composite turns out to be significantly less costly than amalgam as a filling material.  Based on conservative assumptions, the following table summarizes the real cost of an amalgam filling in the U.S., presented in the form of two alternative approaches for calculating the “external” costs of using mercury in dentistry:

1.      The first approach, which is more conservative than the second, is to estimate the additional cost (i.e., beyond measures already being taken) required to keep dental mercury out of the environment, or at least to minimize the amount that reaches the environment.^[6]  These include measures such as removing mercury from the flue gases of incinerators and crematoria, removing mercury from wastewater sludges before disposal to agricultural land, collecting and recycling dental amalgam waste and sequestering the recovered mercury, etc.  Since there is an international consensus that the global pool of mercury circulating in the biosphere needs to be greatly reduced, it is logical to calculate the cost of ensuring that additional mercury does not enter the environment from dental uses.  Using this approach, the cost of keeping 90% of 2009 mercury releases associated with amalgams out of the environment adds an extra $41-67 to the commercial cost of an amalgam filling.

2.      The second approach quantifies the benefits for people and the environment that would result from a phase-out of mercury use in dentistry.  These would include such benefits as reduced health costs, reduced environmental effects, additional jobs created, etc.  In most cases these benefits are simply the same as “avoided costs.”  Using this approach, the annual benefits that would be accrued if composite fillings were placed instead of amalgam amounts to $3.1-6.5 billion.  When allocated over the roughly 51 million amalgams placed in 2009, this amounts to $60-128 for each amalgam avoided, raising the real cost of amalgam even higher than under the first scenario.

Average dental clinic fee vs. the real cost of an average (“equivalent”) amalgam filling

While this report focuses on amalgam use only in the U.S., this case should serve as a valuable example for other nations that are contemplating the future of dental amalgam in their own countries.  Clearly, the general trend is in the direction of mercury-free dentistry.

The Swedish ban on amalgam effective 1 June 2009 has proven that there are few if any cases where amalgam fillings are necessary (KEMI 2010).  As amalgam is similarly banned in Norway and Denmark, and severely restricted in Germany, Finland, Bulgaria, Mongolia, Vietnam, Thailand (WHO 2010) and Japan, among others, the mercury-free experience in these countries clearly demonstrates that amalgam is no longer necessary in most clinical situations.[7]

Support for mercury-free dentistry is gaining momentum internationally, with a recent World Health Organization report recognizing the environmental concerns of amalgam and the need “to prepare for a treaty on mercury use,” including support for use of dental material alternatives to amalgam (WHO 2010).  Leading up to and during the 3^rd Intergovernmental Negotiating Committee meeting (November 2011) for a legally binding agreement on mercury, the Nordic Council, Switzerland and the African Region all expressed support for a dental amalgam phase-out.  The Council of Europe has also recently passed a resolution calling on nations to take measures “restricting or prohibiting the use of amalgam for dental fillings” (Council 2011).

Among other scientific assessments, the Scientific Committee on Emerging and Newly Identified Health Risks has concluded that modern mercury-free alternatives “have facilitated a radical change in the concepts of restorative dentistry through the introduction of more minimally invasive techniques and the associated retention of more tooth substance when treating caries” (SCENIHR 2008).

In summary, the methodical research presented in this report confirms that amalgam is by no means the least expensive filling material when the external costs are taken into account.  Clearly, adverse effects on the environment and society over the whole life cycle of dental amalgam – mercury production, preparation of filling materials, removal of old fillings and placement of new ones, environmental and health impacts from mercury recycling, discharges to wastewater, solid waste disposal, emissions from crematoria and releases from cemeteries – can only be sustainably avoided by phasing out amalgam as a dental restorative material and switching to mercury-free alternatives.^[8]  Since high quality and cost-effective alternatives – including composites, glass ionomers and “compomers” – are readily available, this report therefore concludes, from a full cost perspective, that dental amalgam should be phased out.^[9]