Many Canadians might be surprised to learn that mercury-containing dental fillings continue to be used in modern dentistry, despite growing environmental concerns about mercury pollution worldwide. While recent international agreements call for phasing out these fillings, medical experts emphasize that existing amalgam fillings pose no significant health risk to patients.
The Reality of Mercury Fillings in Modern Dentistry
Dental amalgam, commonly known as silver fillings despite containing approximately 50% mercury, has been a cornerstone of dental care for over a century. These durable restorations became popular because they withstand the forces of chewing exceptionally well and typically last longer than many alternative materials. The remaining composition includes other metals like silver, tin, copper, and zinc, creating a strong, reliable dental restoration.
Dr. Christopher Labos, a Montreal physician, notes that while mercury fillings have become less common in recent years, they haven't disappeared from dental offices entirely. Many dentists still use them, particularly in situations where strength and longevity are paramount considerations.
International Regulations and Health Concerns
The recent Minamata Convention COP-6 conference has called for a global phase-out of dental amalgam by 2034. This international treaty, named after the Japanese city that suffered devastating mercury poisoning in the mid-20th century, aims to reduce mercury pollution worldwide.
Mercury's toxicity is well-documented. In large doses, mercury can cause neurological damage, kidney problems, and lung irritation. The classic example comes from Lewis Carroll's Mad Hatter character, inspired by real 18th and 19th-century hat makers who developed neurological symptoms from chronic mercury exposure during felt production.
However, the minimal amounts of mercury released from dental fillings fall far below dangerous levels. The World Health Organization estimated daily mercury exposure from dental amalgam at just 10 micrograms per day in 1991, while Health Canada's 1996 report provided an even lower estimate of 3.4 micrograms daily—both well below toxic thresholds.
Why Removing Existing Fillings Isn't Recommended
Despite the alarming associations with mercury toxicity, dental professionals unanimously advise against preemptively removing existing amalgam fillings. The process of removal can actually release more mercury than simply leaving the fillings in place, potentially causing more harm than good.
As a precautionary measure, Health Canada recommends against using dental amalgam in children, pregnant women, and people with kidney disease. For the general population, however, the consensus within medical and dental communities remains that amalgam fillings are safe.
The broader phase-out of mercury focuses primarily on environmental concerns rather than direct health risks from dental applications. Mercury used in artisanal gold mining and certain cosmetics poses a much greater threat, as these practices contribute significantly to environmental contamination that enters the food chain through fish and other seafood.
For Canadians with existing mercury fillings, the advice from experts is clear: don't rush to have them removed. While the dental industry moves toward mercury-free alternatives, your existing amalgam fillings aren't putting your health at risk.
