Should I be concerned about my dental amalgam (silver) fillings? How do I know if I’m suffering from mercury toxicity?
The topic of amalgam (silver-colored) fillings has been researched, reviewed, studied and restudied for years. As technology advances, research reveals more about the potential effects of mercury vapor exposure in the body and how it affects oral health.
By the end of this article, you should know the following:
- What silver fillings are
- Why dental amalgam fillings are controversial
- Potential effects of mercury vapor exposure to the body
- Alternative dental filling materials
- Options to minimize effects of mercury exposure (amalgam fillings removal is not the only option)
- What to know about having silver fillings removed
- How to find the right dentist, if fillings removal is the option you choose
- Simple ways to detox mercury from the body
What are amalgam dental fillings and why are they controversial?
Amalgam dental fillings (also referred to as metal, silver, or silver-colored fillings) are composed of a mixture of metals to form a soft, plastic-like substance. This easily moldable substance is then placed and formed into the space where tooth decay has been drilled out, then hardens.
This type of filling, like other dental fillings, serves as a way to produce living tooth structure in teeth with small-to-medium cavities.
First introduced to the dental community in the 1830s, dental materials made from amalgam have been around in practice for nearly 200 years. The earliest use of dental amalgam actually goes all the way back to 659 AD.
Throughout the past 2 centuries, there have been various discussions and controversies over the use of silver fillings. Some felt it was an inferior material, others have questioned its safety.
But even after 25+ years of an upswing in research and skepticism over the use of amalgam fillings, they are still widely and frequently used as one of the top cavity fillers throughout the world.
There are a number of reasons for this:
- Cost: Amalgam is the least expensive medium for fillings. Although other materials, such as composites/resin and gold inlays/onlays, are considered safer and long-lasting, they are more expensive. This cost difference can be as high as 10+ times the price.
- Availability: Dentists offer amalgam fillings. They may recommend composite fillings (which more closely match the color of your teeth) for teeth that will be seen when you smile. But because it is less expensive and the most commonly used, amalgam is often chosen for the larger back teeth, unless the patient requests another material.
- Speed: Amalgam is so easily manipulated and pliable, inserting and shaping the filling is a relatively quick process. This is great for those with dental anxiety and children who have a tough time sitting still.
Amalgam’s Chemical Composition
According to Wikipedia, dental amalgam is a liquid mercury and metal alloy mixture. Low-copper amalgam is composed of 50% mercury, 22-32% silver, 14% tin and 8% copper, along with some other trace metals.
The Amalgam Controversy
The questions of amalgam use and decisions like choosing amalgam versus composite have surfaced a number of times over the past two centuries.
Once amalgam fillings were introduced on the scene in the 1830s, some practitioners considered it an inferior option.
Before the American Dental Association (ADA) was founded in 1859, the American Society of Dental Surgeons (ASDS) took the stand that using silver fillings was tantamount to malpractice. They went as far as to require its members to submit a signed statement/pledge that they would not use amalgam at all.
This sparked what has been called the “Amalgam War,” pitting dentists on either side of this argument against each other. However, by the time the ASDS disbanded in 1856 and the American Dental Association was founded just three years later, the ban on silver fillings was not spoken or heard of for some time.
At that point, the newly formed ADA decided that, with advances in science and dentistry techniques, the use of amalgam was perfectly acceptable. Once this was the established norm, silver dental fillings have been used by the vast majority of dentists around the world.
In the past 30 years, however, the question of mercury fillings’ safety has arisen in the medical community. Many are concerned about the amalgam fillings side effects on the body.
I want to be candid with you about this: there are strong opinions on both sides of this issue. Much research exists to support and decry the safety of using amalgam dental fillings.
If you explore the information on both sides, I think you’ll find that many of the articles in support of continuing use of amalgam dental fillings have issues. Many of these studies are grossly limited in scope, or their parameters are over- or understated.
The ADA regularly posts statements supporting the safe use of mercury silver fillings (as recently as March 2019), usually due to the low levels of mercury present in mercury amalgam. These statements come from a number of worldwide health-related organizations.
The post is not a scientific document, per se; it is purely an endorsement of amalgam fillings.
Here is another supporting article from the Scientific Committee on Emerging and Newly Identified Health Risks (SCENIHR). The study, published in May 2008, claims to have solid evidence in complete favor of amalgam as a safe material for dental fillings.
In January 2011, an article was published in the Journal of Occupational Medicine and Toxicology that succinctly took apart the SCENIHR report, piece by piece. (1) They open the rather lengthy abstract with this statement:
“SCENIHR disregarded the toxicology of mercury and did not include most important scientific studies in their review. But the real scientific data show that:
(a) Dental amalgam is by far the main source of human total mercury body burden. This is proven by autopsy studies which found 2-12 times more mercury in body tissues of individuals with dental amalgam. Autopsy studies are the most valuable and most important studies for examining the amalgam-caused mercury body burden.
(b) These autopsy studies have shown consistently that many individuals with amalgam have toxic levels of mercury in their brains or kidneys.
(c) There is no correlation between mercury levels in blood or urine, and the levels in body tissues or the severity of clinical symptoms. SCENIHR only relied on levels in urine or blood.
(d) The half-life of mercury in the brain can last from several years to decades, thus mercury accumulates over time of amalgam exposure in body tissues to toxic levels. However, SCENIHR state that the half-life of mercury in the body is only “20-90 days”.
(e) Mercury vapor is about ten times more toxic than lead on human neurons and with synergistic toxicity to other metals.
(f) Most studies cited by SCENIHR which conclude that amalgam fillings are safe have severe methodical flaws.”
This counter to the 2008 report is full of links to other substantiating studies and references, clearly laying out a pattern of shallow research and case studies on the part of the SCENIHR.
As comparison, you may be interested to read the official statement of the US Food and Drug Administration (FDA). In that statement, the FDA discusses that amalgam fillings were reassigned to a higher risk level on the scale of medical devices.
The bottom line? There’s research on both sides that may or may not support the use of metal fillings.
Signs and Symptoms of Mercury Toxicity
There are a number of factors to consider when questioning if symptoms are related to chronic mercury poisoning, directly or indirectly.
Before I list facts and symptoms that may be connected to mercury poisoning, it may be helpful to know a few medical facts from Mayo Clinic about safe mercury levels in the blood. Interestingly enough, the Mayo clinic is one of the organizations from which the ADA posted a supporting statement about the safety of silver dental fillings.
Here’s what the Mayo Clinic has to say about safe mercury levels:
- “A small amount of mercury (2-20 mcg/day) is released from a dental amalgam when it was mechanically manipulated, such as by chewing. The habit of gum chewing can cause release of mercury from dental amalgams greatly above normal. Additional: other mechanical manipulation occur due to bruxism (grinding your teeth) and added heat from dental procedures or dental cleanings.
- “The World Health Organization safety standard for daily exposure to mercury is 45 mcg/day. Thus, if one had no other source of exposure, the amount of mercury released from dental amalgams is not significant.
- “However, “many foods contain mercury. For example, commercial fish considered safe for consumption contain <0.3 mcg/g of mercury, but some game fish contain >2.0 mcg/g and, if consumed on a regular basis, contribute to significant body burden.”
Here are the top factors when determining your body’s mercury burden to make a decision whether or not to have amalgam fillings removed:
- How many mercury fillings you have
- How often/how long they’re stimulated (whether by chewing, teeth grinding or contact with restorative materials)
- The specific kind of stimulation, including heat and contact of amalgam restorations
- How long you’ve had the fillings
- How much you’re exposed to mercury from other sources, like game fish
Here are the most notable amalgam fillings side effects according to The Academy of Oral Medicine and Toxicology:
- Respiratory issues
- Cardiovascular issues
- Endocrine disruptors
- Immune system impairment
- Mood changes and other psychological problems (nervousness, depression, etc.)
- Emotional instability
- Loss of hearing
- Loss of appetite
- Decreased sleep, insomnia
- Weight loss
- Overall weakness
- Skin changes
Who is most at risk with amalgam dental fillings?
As we consider the health risks of too much mercury exposure from dental amalgam fillings, I want to discuss who may be considered high risk, due to certain life changes or medical situations.
There is much scientific evidence about the dangers of mercury exposure and effects in human infant and fetal tissues. (2) This means pregnant women and nursing mothers need to be very mindful of the potential effects of release of vapors.
Mercury can be released and absorbed in other ways besides chewing, like when you grind your teeth or eat fish that contain mercury. The adverse health effects of and risk of amalgam poisoning should be discussed with a reputable functional dentist.
Each year you have amalgam fillings in your mouth, higher amounts of mercury are released. Because mercury bioaccumulates over time and depending on their age, elderly people may have had far more fillings over the course of a lifetime.
As many elderly folks become more aware of their health problems and special dietary needs as they age, they may consume more fish as a result. While this is great for heart health, it might not be so good for mercury exposure.
Many types of fish are high in mercury content—for these, it’s important to eat these in small portions and not often.
In addition, if you are able to keep your teeth as you age, you’ll likely go through more amalgam restorations, or other dental restoration. These can involve restorative materials that touch or contact with mercury amalgam.
According to an article from the NRDC (National Resources Defense Council):
“Even small amounts of mercury can interfere with brain development, making exposure particularly risky for children younger than six.”
People with Mutations of the MTHFR Gene
I know what you’re thinking… “What did you say?” But, although it looks like an abbreviated swear word, MTHFR stands for methylenetetrahydrofolate reductase. A lot of people have this mutation and are, therefore, at a higher risk of mercury toxicity from silver fillings. (3)
Professionals Who Work with Mercury
This group is probably the one requiring the least explanation. You’ve probably read how asbestos exposure in the workplace has been found to potentially cause a range of health issues.
Similarly, employees whose job requires them to work around or with mercury can greatly increase their chances of health problems, since mercury bioaccumualates over time.
As was stated earlier, mechanical manipulation releases mercury vapors into our system. Our mind automatically goes to eating/chewing food. However, every time your teeth grind together is an additional release.
Make sure to ask your dentist if you show signs of grinding at your next cleaning. While you might know you’re a bruxer if you grind your teeth during the day due to stress, many people grind during sleep without realizing it.
Patients with Extensive Dental Work
Patients who go through extensive dental work, amalgam restorations, and other repair/replacement procedures are also at a higher risk of mercury toxicity.
Anytime a dental amalgam filling is touched or drilled, there is a possibility of mercury particles or pieces spraying in your mouth, or even being swallowed. Before getting in the dentist’s chair, ask about potential for allergic reaction, as well as symptoms that may indicate, or be a result of mercury poisoning.
What to Do About Amalgam Fillings
Not everyone needs to rush to the dentist to have amalgam fillings removed. Amalgam fillings removal may not be the only answer.
After reading the studies about the effects of mercury, folks may rush to the decision to have the fillings removed as soon as they can make an appointment. (4)
However, there is much scientific evidence about the high levels of mercury that can be released in your mouth and body from the removal of silver fillings. (5)
Keep that in mind if you decide to get your silver fillings taken out.
Want your amalgam fillings removed? Here’s what to do.
1. Find a Dentist You Trust
The first thing I would recommend you do before having amalgam dental fillings removed is to find a functional dentist who will evaluate your dental and overall health as a whole.
There are stark contrasts between functional dentistry and traditional dentistry. Both kinds receive the same training and require the same hours of schooling/internship, etc.
Here are some places you might look to find a functional dentist in your area:
- Holistic Dentistry
- Campaign for Mercury-Free Dentistry
- International Academy for Biologic Dentistry and Medicine (IABDM)
- Huggins Applied Dentistry (this requires an application for the organization to connect you with an appropriate dentist)
- Mercury-Safe Dentistry Directory
Search for a functional dentist in your area and see what s/he has to offer. Compare with a traditional dentist’s office and look up ratings and/or reviews.
I no longer offer or use amalgam fillings in my own practice. But when it comes to the question of what to do with existing silver fillings, there are several things to consider. How many times has this dentist done the procedure? What symptoms of mercury toxicity is s/he looking for?
2. Be Prepared to Detox
The most important step you can take to counteract the amount of mercury released from silver fillings is to evaluate your diet. This is especially important when having your fillings removed, since you’re exposing your body to a high dose of mercury for a short period of time in order to get the filling out.
Try eating these foods before and after getting fillings removed (they’re also great for detoxing from mercury exposure, even without removing your fillings):
- High alkaline foods
- Liver-supporting foods
- High B12 and folate foods
- Cilantro (ideally, 3 servings a day)
Increasing your intake of cilantro can be a beautifully simple detox. Not only does it act as a natural detox from mercury and other metals, cilantro (in Britain, known as coriander), it has numerous other health benefits:
- Lead detoxification: There is evidence (from a study on rats) that coriandrum sativum (Chinese parsley) can suppress lead accumulation in the body. (6)
- Anticancer effects: Some studies have indicated that cilantro (and some other spices), can decrease HCA (heterocyclic amine) from forming in meats before they are cooked. (7) These compounds are known to be carcinogens.
- Anti-inflammatory properties: A 2010 study indicates wins in decreased pain and inflammation with the use of cilantro/coriander. (8)
- Antioxidant benefits: Consuming coriander carotenoids (a type of antioxidant) has been shown to “strongly scavenge hydroxyl radicals,” one of the most powerful agents of oxidative stress. (9)
- Skin Health: Animal tests indicate that eating cilantro can protect skin against UVB radiation damage by preventing skin photoaging. (10)
Other ways you can support your body’s natural detoxification process if you’ve been exposed to mercury may include:
- Using a small amount of activated charcoal as a supplement to your diet. Charcoal binds to heavy metals in your body and allows you to excrete them more efficiently.
- Sweat more, whether by intense exercise or using a sauna or other high-heat environment. Sweating is one part of your body’s normal “detox” process.
3. Limit Other Mercury Sources
Limit your intake of these fish (list is not all-inclusive):
- Tuna (highest levels of mercury in bigeye, lower amounts in albacore and yellowfin)
- Orange roughy
- King mackerel
- Mahi mahi
4. Watch for Symptoms of Mercury Poisoning
After the procedure, be aware of any potential symptoms of mercury toxicity listed in the “signs and symptoms” section of this article. If you are concerned about mercury poisoning based on any symptoms you notice, call your dentist right away.
Getting a new filling? Choose these filling types instead.
Should your dentist ever find tooth decay through exam or x-rays, ask about safer alternative dental filling materials in your treatment options. I’ve listed these in a generally low-to-high price range.
Porcelain: Also known as inlays or onlays, porcelain fillings are also able to be matched to your natural teeth color. This dental filling material usually requires more than one visit to complete the process.
The first step is to be fitted, at which point an impression is made and sent away to be molded/shaped. The second step involves bonding the filling to the tooth. Good inlays can last 15-20 years.
Composite Resin: Probably the most commonly used filling material after amalgam is composite. Usually composed of glass and acrylic resin, this material is most frequently used in front teeth that are most visible.
Although not quite as durable as other options, composite fillings can last as long as 10 years. When used to fill smaller cavities, or decay on teeth that aren’t “heavy chewers,” composite fillings are an excellent choice.
Gold Inlay/Onlay: Being literally the “gold standard” of dental fillings, this material is not only one of the longest lasting and most durable, it is the most expensive.
A con of gold inlay/onlay fillings is that a cast must be made from a mold of your teeth, then the material is poured in at a separate visit. But there are a lot of pros: gold is well tolerated by gum tissue and wears at a consistent rate with your natural bite.
Although gold fillings are generally considered to last 15-20 years, some can safely last as long as 30-40 years.
Key Takeaways: Amalgam, and What to Do About It
As you’ll find with even minimal amount of research on the topic, much has been written and studied about the short- and long-term effects on the body of amalgam fillings and mercury exposure.
For some people, mercury toxicity is a real concern and may lead to the decision to have these fillings removed. For others, a diet high in health-promoting foods that encourage detoxification is the right option for handling silver fillings.
I hope this article has provided a summary of the complex science behind amalgam fillings. If you have more questions on this topic, just ask me.Read Next: When You Need a Dental Filling, and What to Expect
- Mutter, J. (2011). Is dental amalgam safe for humans? The opinion of the scientific committee of the European Commission. Journal of Occupational Medicine and Toxicology, 6(1), 2. Full text: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3025977/
- Drasch, G., Schupp, I., Höfl, H., Reinke, R., & Roider, G. (1994). Mercury burden of human fetal and infant tissues. European journal of pediatrics, 153(8), 607-610. Abstract: https://www.ncbi.nlm.nih.gov/pubmed/7957411
- Austin, D. W., Spolding, B., Gondalia, S., Shandley, K., Palombo, E. A., Knowles, S., & Walder, K. (2014). Genetic variation associated with hypersensitivity to mercury. Toxicology international, 21(3), 236. Full text: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4413404/
- Fernandes Azevedo, B., Barros Furieri, L., Peçanha, F. M., Wiggers, G. A., Frizera Vassallo, P., Ronacher Simões, M., … & Stefanon, I. (2012). Toxic effects of mercury on the cardiovascular and central nervous systems. BioMed Research International, 2012. Full text: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3395437/
- Warwick, R., O’Connor, A., & Lamey, B. (2013). Mercury vapour exposure during dental student training in amalgam removal. Journal of Occupational Medicine and Toxicology, 8(1), 27. Full text: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3850894/
- Aga, M., Iwaki, K., Ueda, Y., Ushio, S., Masaki, N., Fukuda, S., … & Kurimoto, M. (2001). Preventive effect of Coriandrum sativum (Chinese parsley) on localized lead deposition in ICR mice. Journal of ethnopharmacology, 77(2-3), 203-208. Abstract: https://www.ncbi.nlm.nih.gov/pubmed/11535365
- Puangsombat, K., Jirapakkul, W., & Smith, J. S. (2011). Inhibitory activity of Asian spices on heterocyclic amines formation in cooked beef patties. Journal of food science, 76(8), T174-T180. Abstract: https://www.ncbi.nlm.nih.gov/pubmed/21913920
- Rajeshwari, U., & Andallu, B. (2011). Medicinal benefits of coriander (Coriandrum sativum L). Spatula DD, 1(1), 51-58. Full text. https://pdfs.nutramedix.ec/Coriandrum%20sativum%20-%20Broad%20Spectrum%20(benifits).pdf
- Divya, P., Puthusseri, B., & Neelwarne, B. (2012). Carotenoid content, its stability during drying and the antioxidant activity of commercial coriander (Coriandrum sativum L.) varieties. Food Research International, 45(1), 342-350. Abstract: https://pubag.nal.usda.gov/catalog/460698
- Hwang, E., Lee, D. G., Park, S. H., Oh, M. S., & Kim, S. Y. (2014). Coriander leaf extract exerts antioxidant activity and protects against UVB-induced photoaging of skin by regulation of procollagen type I and MMP-1 expression. Journal of medicinal food, 17(9), 985-995. Full text: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4152784/