Are mercury fillings (amalgam fillings) dangerous to human health?

Mercury Fillings and Health Risks

Mercury dental fillings (amalgam) are generally safe for most people, but they do contain mercury which is a known environmental toxin that requires proper handling and disposal.

Mercury in Dental Amalgam

Dental amalgam fillings contain approximately 50% mercury along with other metals including silver, tin, copper, and zinc 1. While these fillings have been used for decades, there are some important considerations regarding their safety:

Safety Profile

• The World Health Organization (WHO) has noted that mercury from dental amalgam contributes to environmental mercury pollution, with more than 50% of total mercury emissions in the United Kingdom coming from dental amalgam and medical devices 1
• In Europe and many other countries, the discharge of dental amalgam waste into wastewater treatment plants is prohibited because mercury is classified as a dangerous substance under European Dangerous Substances Directive 1

Risk Assessment for Patients

Mercury exposure from dental amalgam occurs primarily through:

1. Vapor inhalation: Small amounts of mercury vapor can be released during chewing
2. Gradual dissolution: Mercury can slowly leach into saliva over time

Evidence on Health Effects

Neurological Considerations

• Mercury is known to be a potent neurotoxin that can affect the central nervous system 2, 3
• The American College of Radiology notes that mercury toxicity can cause cerebellar effects including ataxia, dysmetria, and tremor 2
• The most significant concern is potential interference with fetal and child brain development, which has been demonstrated in animal studies 3

Special Population Considerations

• Pregnant women and children: Should exercise particular caution regarding mercury exposure 2
• Individuals with genetic polymorphisms: May have varying sensitivity to mercury exposure 3
• Patients with neuromuscular conditions: Case reports suggest possible exacerbation of symptoms in some individuals 4

Recommendations Based on Current Evidence

1. For general population: Current evidence does not support routine removal of intact amalgam fillings in asymptomatic individuals 5

2. For pregnant women and children: Consider alternative dental filling materials when possible 2

3. For new fillings: Consider non-mercury alternatives that are now widely available

4. For dental professionals: Implement proper mercury handling protocols to minimize occupational exposure and environmental contamination 6

Important Caveats

• The risk of side effects from dental amalgam appears to be low (likely below 1%) based on epidemiological evidence 3
• Mercury release from dental amalgam does not present an unacceptable risk to the general population according to evaluations from various health agencies 5
• Unnecessary removal of amalgam fillings can temporarily increase mercury exposure during the removal process 5

Conclusion

While dental amalgam fillings do contain mercury, the scientific consensus suggests they pose minimal risk to most patients. However, prudent avoidance in vulnerable populations and consideration of alternative materials for new fillings represents a reasonable approach based on current evidence.