Long term changes in health complaints after removal of amalgam restorations

Abstract

Objective: Concerns over adverse effects of mercury released from dental amalgam sometimes lead patients to request removal of their amalgam restorations. Several studies report improvement of subjective health after removal of amalgam restorations, but the mechanisms are unclear. The aim of this paper is to present data on long term changes in intensity of health complaints after amalgam removal in a group of patients with health complaints self-attributed to dental amalgam. Data from the five years follow-up in a clinical trial are presented and related to potential determinants of change.

Materials and methods: Patients previously referred to a specialty unit for health complaints attributed to amalgam restorations were included in the study. The 20 participants who were allocated to the treatment group had all amalgam restorations removed and replaced with other dental restorative materials. Intensity of health complaints was calculated from questionnaire data and personality variables were measured by MMPI-2.

Results: At the follow-up five years after the amalgam removal was completed, intensity of general health complaints was significantly reduced (p=.001), but the symptom load was still high. The reduction was significantly correlated with concentration of mercury in urine at pre-treatment. There were no significant correlations with personality variables.

Conclusions: Removal of amalgam restorations was followed by a long term reduction of general health complaints, which was associated with mercury concentration in urine before amalgam removal. Additional studies are needed to confirm the potential mechanisms for the observed reduction.

Keywords:

• Dental amalgam
• mercury
• personality tests
• subjective health complaint

Acknowledgements

Vigdis Helland is acknowledged for excellent administrative help. Siren Hammer Østvold and Randi Sundfjord are acknowledged for excellent technical assistance.

Disclosure statement

The authors have no conflicts of interest to declare.

Notes on contributors

LB conceived of the study, served as principal investigator, had the primary responsibility for statistical analysis and wrote the manuscript; TTS collaborated in collection, analysis and interpretation of the data and writing the manuscript; KD collaborated in study design, was responsible for the personality tests, participated in the clinical part of the study, collaborated in interpretation of the data and in preparation of the manuscript; GBL collaborated in study design, analysis and interpretation of the data and writing the manuscript; TLLB collaborated in the clinical study, interpretation of the data, and writing the manuscript; JS collaborated in the clinical study, interpretation of the data and in preparation of the manuscript; BFL collaborated in study design, participated in the clinical part of the study, and in preparation of the manuscript.

Additional information

Funding

The Norwegian Dental Biomaterials Adverse Reaction Unit is funded by the Norwegian Ministry of Health and Care Services.