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Calle Bengtsson was born 1934
in the town Alingsås in a beautiful rural area of central Sweden. Until 1985, he served
in internal medicine at Sahlgrenska Sjukhuset in Gothenburg. From a scientific point of
view, he was mainly an epidemiologist, trained by the iron hematologist Leif Hallberg and
the general practitioner Gösta Tibblin. Calle Bengtsson served as professor of family
medicine at the University of Gothenburg 1985-1999. He is the editor of Scandinavian
Journal of Primary Health Care since 1996. |
Amalgam challenged!
During the latest 20 years the potential influence from dental amalgam fillings
and the release of mercury from these fillings has been discussed quite a lot. Different
symptoms as well as possible damage of brain, kidneys and the immunological system have
been in the focus of discussion.
Population study
A population study of women was carried out in 1968-69 in Gothenburg, Sweden with 1462
participants and a participation rate of 90.1% and with follow-ups later on. The results
presented here refer to the 12-year and 24-year follow-ups. By means of a panoramic X-ray
and colour slides the number of dental fillings at the time of the basal study could be
assessed. At the follow-up studies the women were asked about prevalence of 30 defined
symptoms, e. g. headache, tiredness, depression, irritability, reduced concentration
capacity and joint pain. End-points such as myocardial infarction, stroke, cancer,
diabetes and overall death were registered based on a careful follow-up. A number of
laboratory examinations were carried out, and serum mercury concentration was measured in
deep-frozen sera.
Amalgam fillings and symptoms
According to primary statistical analyses there were reversed associations between number
of amalgam fillings and several of the symptoms which were studied. There was also a
strong correlation between number of remaining teeth and amalgam fillings. When taking
number of teeth and a number of socio-economic factors into consideration as background
variables in the statistical analysis, must of these significant correlations disappeared,
but no correlation changed direction. We could conclude that there was no correlation
between increased number of amalgam fillings and increased prevalence of symptoms. Similar
results were observed when the same variables were associated with serum mercury
concentration instead of amalgam fillings.
Amalgam fillings and diseases
There were some reversed correlations between amalgam fillings and some of
the end-points studied but none of statistical significance when taking background
variables into consideration. The results were similar when studying serum mercury
concentration instead of number of fillings. We could conclude that there was no
association between number of amalgam fillings or serum mercury concentration and the
end-points studied.
Chemical blood and urinary analyses. The
number of amalgam fillings were associated with altogether 54 different chemical analyses.
We observed no effects on renal function, liver function, immune globulins which could be
ascribed to amalgam fillings.
Discussion and conclusions
We had exceptionally good possibilities to study the potential effect on health from
amalgam fillings. Data from the Population Study of Women had been collected before the
amalgam discussion had started, and number of fillings and symptoms and end-points had
been studied independent of each other. As there is an association between socio-economic
factors and dental health, socio-economic factors must be taken into consideration in
statistical analyses. After doing so there was, if anything, a tendency towards an
association between number of amalgam fillings and good health. There was an association
between number of amalgam fillings and serum mercury concentration, but when studying
serum mercury concentration instead of amalgam fillings, the results were similar.
In summary, we have looked for an increase of
symptoms and diseases as a consequence of amalgam fillings, but we did not find such an
association. It is important to point out that our population based results cannot tell us
if there are single persons who have symptoms or other negative effects of amalgam.
However, we can conclude from our epidemiological studies that this is not very common.
Calle Bengtsson
References
- Bengtsson C, Ahlqwist M, Bergdahl IA, Lapidus L,
Schütz A. Inget samband mellan antal amalgamfyllningar och hälsa. Epidemioloigska
erfarenheter från populationsstudie av kvinnor i Göteborg. Läkartidningen
2001;98:930-3.
- Ahlqwist M, Bengtsson C, Furunes B, Hollender L,
Lapidus L. Number of amalgam tooth fillings in relation to subjectively experienced
symptoms in a study of Swedish women. Community Dent. Oral Epidemiol. 1988; 16: 227-31.
Ahlqwist M, Bengtsson C,
Lapidus L. Number of amalgam fillings in relation to cardiovascular disease, diabetes,
cancer and early death in Swedish women. Community Dent. Oral Epidemiol. 1993; 21: 40-4.
Ahlqwist M, Bengtsson C,
Lapidus L, Lindstedt G, Lissner L. Concentrations of blood, serum and urine components in
relation to number of amalgam tooth fillings in Swedish women. Community Dent. Oral
Epidemiol. 1995; 23: 217-21.
Bergdahl IA, Schütz A,
Ahlqwist M, Bengtsson C, Lapidus L, Lissner L, Hultén B. Methylmercury and inorganic
mercury in serum – correlation to fish consumption and dental amalgam in a cohort of
women born in 1922. Environ. Res. 1998;77:20-4.
- Ahlqwist M, Bengtsson C, Lapidus L, Bergdahl IA,
Schütz A. Serum mercury concentration in relation to survival, symptoms, and diseases:
results from the prospective population study of women in Gothenburg, Sweden. Acta
Odontol. Scand. 1999; 57:168-74.