The association between amalgam dental surfaces and urinary mercury levels in a sample of Albertans, a prevalence study

Daniel J Dutton,Ludovic Brunel,Peter Faris,Ken Fyie,Jc Emery

doi:10.1186/1745-6673-8-22

Daniel J Dutton, Ludovic Brunel + Show 3 more

Open Access

https://doi.org/10.1186/1745-6673-8-22

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Abstract

ObjectiveThe objective of this study was to quantify the relationship between number of dental amalgam surfaces and urinary mercury levels.MethodsThis study uses participant data from a large philanthropic chronic disease prevention program in Calgary, Alberta, Canada. Urine samples were analysed for mercury levels (measured in μg/g-creatinine). T-tests were used to determine if differences in urine mercury were statistically significant between persons with no dental amalgam surfaces and one or more dental amalgam surfaces. Linear regression was used to estimate the change in urinary mercury per amalgam surface.ResultsUrinary mercury levels were statistically significantly higher in participants with amalgam surfaces, with an average difference of 0.55 μg/g-creatinine. Per amalgam surface, we estimated an expected increase of 0.04 μg/g-creatinine. Measured urinary mercury levels were also statistically significantly higher in participants with dental amalgam surfaces following the oral administration of 2,3-dimercaptopropane-l-sulfonate (DMPS) and meso-2,3-dimercaptosuccinic acid (DMSA) which are used to mobilize mercury from the blood and tissues.DiscussionOur estimates indicate that an individual with seven or more dental amalgam surfaces has 30% to 50% higher urinary mercury levels than an individual without amalgams. This is consistent with past literature that has identified seven amalgam surfaces as an unsafe level of exposure to mercury vapor. Our analysis suggests that continued use of silver amalgam dental fillings for restorative dentistry is a non-negligible, unnecessary source of mercury exposure considering the availability of composite resin alternatives.

Highlights

Amalgam dental surfaces are popular in dentistry and have been for decades
A sizeable body of research suggests that dental amalgams are a major source of mercury exposure in the general population, with several studies showing a correlation between the number of amalgam surfaces and brain, blood and urinary concentrations of mercury [3,4,5,6,7,8,9,10,11,12,13]
We find that individuals with one or more dental amalgam surfaces have, on average, at least double the urinary mercury level of individuals with no dental amalgam surfaces

Summary

Introduction

Amalgam dental surfaces are popular in dentistry and have been for decades. They contain approximately 50% mercury in combination with other metals including silver and copper [1]. The use of dental amalgams has always been a source of controversy because of the potential health risks associated with exposure to mercury. Dental amalgams have been correlated with disease outcomes, for instance, kidney function in children [14] or neurological degeneration in adults (e.g., Alzheimer’s disease) [15]. High levels of mercury in the diet, an allergy to mercury, impaired kidney function, and environmental or workplace exposure to mercury are all contraindications for dental amalgams according to Health Canada [16,17]

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