Changes in health complaints after removal of amalgam fillings

T T Sjursen, G B Lygre, K Dalen, V Helland, T Laegreid, J Svahn, B F Lundekvam, L Björkman, T T Sjursen, G B Lygre, K Dalen, V Helland, T Laegreid, J Svahn, B F Lundekvam, L Björkman

Abstract

The aim of the present study was to investigate whether removal of all amalgam fillings was associated with long-term changes in health complaints in a group of patients who attributed subjective health complaints to amalgam fillings. Patients previously examined at the Norwegian Dental Biomaterials Adverse Reaction Unit were included in the study and assigned to a treatment group (n = 20) and a reference group (n = 20). Participants in the treatment group had all amalgam fillings replaced with other restorative materials. Follow-ups took place 3 months, 1 and 3 years after removal of all amalgam fillings. There was no intervention in the reference group. Subjective health complaints were measured by numeric rating scales in both groups. Analysis of covariance was used to compare changes in health complaints over time in the two groups. In the treatment group, there were significant reductions in intra-oral and general health complaints from inclusion into study to the 3-year follow-up. In the reference group, changes in the same period were not significant. Comparisons between the groups showed that reductions in intra-oral and general health complaints in the treatment group were significantly different from the changes in the reference group. The mechanisms behind this remain to be identified. Reduced exposure to dental amalgam, patient-centred treatment and follow-ups, and elimination of worry are factors that may have influenced the results.

© 2011 Blackwell Publishing Ltd.

Figures

Fig. 1
Fig. 1
Participant flow. Flow diagram showing participant flow in the study. The study is a before-and-after study with a comparison group (reference group). aCurrent addresses were missing for 10 patients; bdid not fulfil inclusion criteria listed in Table 1; cexcluded according to exclusion criteria listed in Table 1; dremoved all amalgam fillings.
Fig. 2
Fig. 2
Timeline for the study. Timeline for the trial for the treatment group and the reference group. Q1, Q2 and Q3 indicate Questionnaire 1, Questionnaire 2 and Questionnaire 3, respectively. Time frames for the activities are indicated for the treatment group (top) and the reference group (bottom).
Fig. 3
Fig. 3
Individual index scores from 3-year follow-up and Questionnaire 3 plotted against scores from Questionnaire 1. Index scores for intra-oral, extra-oral and general health complaints from treatment group (left column) at 3-year follow-up plotted against index scores before amalgam removal (Questionnaire 1). For the reference group (right column), index scores from Questionnaire 3 were plotted against index scores from Questionnaire 1. Data from intention-to-treat analyses (last value carried forward) are marked with grey dots in the diagrams. Results from statistical analyses of data are given in Table 3.
Fig. 4
Fig. 4
Mean mercury concentration in serum and urine at pre-treatment examination and at follow-up after removal of amalgam fillings. Mean mercury concentration (and s.d.) in serum (nmol L−1) and urine (nmol per mmol creatinine) at pre-treatment examination and at follow-up after removal of amalgam fillings. Mercury concentration in both serum and urine was significantly reduced after amalgam removal (P < 0·001, and P = 0·004, respectively).

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Source: PubMed

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