Dental fillings: a concern for your health? Safety of dental amalgam
and alternative dental restoration materials
Context - In light of recent scientific studies on dental amalgam, SCENIHR revisited its 2008 opinion on the safety and performance of both dental amalgam and possible alternatives (i.e. resin-based composites, glass ionomer cements and ceramics).
Mercury, which is the metallic element used in dental amalgam fillings, has well-documented and well-known health effects. Do dental amalgam and alternative materials pose any risks?
1. What is dental amalgam?
Dental amalgam is an alloy of
mercury (about 50%) with other
metals, usually silver, tin and copper. Dental
amalgam has been used for over 150
years for the treatment of dental cavities. It has long been and still is
considered the material of choice because it is durable, very hard and
inexpensive. However, dental amalgam is not tooth-coloured and does not adhere
to remaining tooth tissues. It is held in
the tooth mechanically and, in comparison with some alternative materials,
requires drilling a relatively large hole and therefore the removal of more
healthy tooth substance.
A reduction in the use of dental amalgam
is occurring across the European Union. This is in line with the concern about
the exposure to mercury from the
environment and with the general aim to reduce mercury use.
2. What are the alternatives for amalgam fillings?
The current trend in dentistry is towards techniques that use minimal
intervention and materials which adhere to the tooth structure. The use of
alternative materials such as ceramics and adhesive composite resins and cements
is increasing. Some alternative materials have been offered in dentistry for
over thirty years. However, many of the alternative materials have only recently
been developed and put into use.
3. Are there any health risks associated with amalgam fillings?
Dental workers are more exposed than the general population
© Marcelo Terraza
The way how mercury is currently used in
dental amalgam is not considered to
endanger the health of the majority of patients. In some cases there are direct
effects in the mouth such as allergic reactions. However, these are relatively
rare and could be resolved by removing the
Available studies do not indicate that dental personnel suffer from adverse
effects from mercury, even though they are
more exposed to it than patients.
4. When is the exposure to mercury from dental amalgam the highest?
Patients are mainly exposed when fillings are placed or removed ©
The highest exposure to mercury occurs
during placement or removal of dental fillings. Accordingly, there is no
justification for unnecessarily removing
amalgam restorations when they do not cause
an allergic reaction. As with any other medical or pharmaceutical intervention,
caution should be exercised for pregnant women when considering the placement or
removal of dental fillings.
5. Are there any health risks associated with the use of alternative materials?
The alternative materials have clinical limitations and may pose toxicological
hazards. However, limited data are available on exposure of patients and dental
personnel to substances that are used in alternative restorative materials. The
available data revealed little evidence of adverse effects. It is important to
note that the composition of resin materials has changed substantially in recent
years and improved polymerisation processes result in a smaller amount of
As the scientific data on possible adverse effects of alternatives are very
limited, the Scientific Committee notes that it is not possible to provide a
scientifically sound statement on the overall safety of these materials. Further
research is needed.
6. Are some dental filling materials preferable?
The opinion of SCENIHR is that for the general population, current evidence
does not preclude the use of either amalgam
or alternative materials in dental restorative treatment. From the perspectives
of longevity, mechanical performance and economics,
dental amalgam is still considered the
material of choice. The dentist should base the choice of material on patient
characteristics such as primary or permanent teeth, pregnancy, presence of
allergies to mercury or other components of
the restorative materials, and eventual decreased renal functioning.
The reasons for this choice should be explained to the patients to help them
make informed decisions.