- Natural Endocrine Solutions Dr. Eric Osansky, DC, IFMCP - https://www.naturalendocrinesolutions.com -

Are Silver Fillings Harmful To Thyroid Health?

Many people have silver fillings, which are also known as mercury amalgams.  I just recently attended a nutritional conference, and one of the presenters mentioned that 80% of people have more than one mercury amalgam.  And while it’s not uncommon for me to work with patients who already had their amalgams removed, most people I work with still have one or more silver fillings.  While getting them removed might seem like a wise decision, sometimes the risks of removing amalgams can outweigh the benefits, which I’ll discuss in this blog post.

It probably makes sense to start off by discussing what a silver filling/dental amalgam is.  Dental amalgam is a mixture of metals, which consists of approximately 50% mercury, and a powdered alloy composed of silver, tin, and copper (1) [1].  While you can see that amalgam fillings do have silver, the main reason they are referred to as “silver fillings” is due to their silver-like appearance.  I’ll use the terms “silver fillings” and “mercury amalgams” interchangeably throughout this blog post.  The reason why they have been used by dentists to fill cavities for many years is because they are long-lasting, and they are the least expensive filling material.

While many dentists no longer recommend mercury amalgams to their patients, unfortunately some dentists still do use these as the primary fillings in their practice.  Keep in mind that even the FDA reveals that low levels of mercury vapor are released by dental amalgams, and can be inhaled and absorbed by the lungs.  And while they still consider dental amalgam fillings to be safe for adults and children (ages 6 and above), there is controversy over this.

What Are The Risks Associated With Silver Fillings?

The International Academy of Oral Medicine and Toxicology (IAOMT) has done a lot of research regarding the risks of dental amalgams.  If you visit their website you’ll see plenty of references showing that mercury vapor is released from dental mercury amalgam fillings at higher rates during brushing, cleaning, clenching of teeth, and chewing.  But why is it a concern to be exposed to mercury, especially when it seems like a small amount?  The reason is because exposure to even small amounts of mercury can have harmful effects, and the same thing applies to other toxic metals.

Mercury Amalgams During Pregnancy and Breastfeeding

According to the American Dental Association (ADA), there is no reliable evidence from controlled studies that exposure to low levels of mercury is associated with any adverse pregnancy outcomes or health effects in newborns and infants (2) [2].  But even if there are no immediate adverse health effects to the baby, does this prove that exposure to low levels of mercury is safe?  While most of my Graves’ disease and Hashimoto’s patients are adults, I do see some children with thyroid autoimmunity.  And while I’m not suggesting that exposure to mercury is the main reason for the development of autoimmune thyroid conditions in children, I don’t think it can be dismissed.

The problem is that it’s not recommended to remove mercury amalgams during pregnancy, which is understandable.  But if there are women reading this with mercury amalgams who are thinking about conceiving in the future, then they might want to first look into getting their amalgams removed before getting pregnant.  Make sure you work with a biological dentist, as not only will they take the proper precautions when removing the amalgams (described below), but they will also give recommendations to help detoxify your body after the amalgams have been removed.

As for breastfeeding when the mother has silver fillings, one study showed that the concentration of breast milk collected after birth showed a significant association with the number of amalgam fillings, although the authors were more concerned about maternal fish consumption during breast feeding (3) [3].  For women who have mercury amalgams, I do think the benefits of breastfeeding outweigh the risks of mercury exposure to the baby.  And truth to be told, there are a lot of other chemicals in breast milk [4] that are passed onto the baby.  That being said, if you plan on getting pregnant and then will breastfeed your baby thereafter you should consider getting your amalgams removed prior to conceiving, along with doing a thorough detoxification.

Testing The Immune Response To Mercury

Most tests for heavy metals measure the LEVELS of mercury, along with other toxic metals.  And while this can be valuable, some people can benefit from tests that measure the IMMUNE RESPONSE to mercury.  The reason for this is because while there is no doubt that it’s best to have low levels of toxic metals, some people react to very low levels of mercury.  For example, it’s possible for someone who has one silver filling to have more health issues than another person who has ten silver fillings, and one reason is because the person’s immune system with the single silver filling might be reacting to mercury, while the person’s immune system with ten silver fillings might not react.  In other words, in some cases the immune system will react to small amounts of mercury.

Fortunately there are tests that have the ability to measure the immune system response to heavy metals (and other chemicals).  One of these is called the Chemical Immune Reactivity Screen, which is from the company Cyrex Laboratories.  This not only measures the immune system response to mercury and other heavy metals, but other chemicals as well, including bisphenol A (BPA), benzene, and parabens.  Another test that can be useful is the MELISA.  This not only can determine if your immune system is reacting to mercury, but to other metals that are commonly found in people’s mouths, including titanium, which is usually used in dental implants.  The way the MELISA works is by testing the patient’s white blood cells against a panel of suspected allergens.

How Does Mercury Affect Thyroid Health?

A few studies show evidence that mercury can have a negative effect on thyroid hormone levels (4) [5] (5) [6].  There is also evidence that mercury might play a role in thyroid autoimmunity, as one study showed that 15 patients who tested positive for a hypersensitivy to mercury using the MELISA test showed a significant decrease in the levels of TPO and thyroglobulin antibodies upon removal of the mercury amalgams (6) [7].  12 patients with thyroid autoimmunity tested negative for mercury hypersensitivity, and they didn’t experience a decrease in thyroid autoantibodies upon removal of mercury amalgams.

It’s also worth mentioning that mercury can be a factor in the development of other autoimmune conditions, and not just Graves’ disease and Hashimoto’s.  For example, there is evidence that mercury can play a role in the development of multiple sclerosis (7) [8] (8) [9].  Another study showed that replacing dental amalgams can benefit the health of those with autoimmune conditions (9) [10].

Should Everyone Get Their Silver Fillings Removed?

Some healthcare practitioners recommend for all of their patients with silver fillings to get them removed immediately.  Without question, in order to be in a state of optimal health you shouldn’t have any mercury in your mouth.  That being said, this doesn’t mean that you need to be free of mercury amalgams in order to get into remission.  In fact, over the years I’ve worked with many people with Graves’ disease and Hashimoto’s who didn’t remove their silver fillings, yet achieved a state of remission.

Once again, in a perfect world none of us would have mercury amalgams.  I do think that most people who have them should eventually get them removed.  And of course when you do this you want to go to a biological dentist, or at the very least a dentist who takes the proper precautions.  But even when getting them removed safely there can be a small risk of mercury leaching into your body, which of course wouldn’t be a good thing for someone who is trying to restore their health.

Then again, let’s revisit the study I mentioned above where people with thyroid autoimmunity who had a mercury hypersensitivity experienced a decrease in autoantibodies upon getting their amalgams removed.  Based on this study, if someone tests positive for a mercury allergy/sensitivity using the MELISA or Cyrex Labs Array #11, then the benefits of getting their mercury amalgams removed probably outweigh any risks.  And once again, the risks are definitely minimal when getting amalgams removed by a dentist who takes the proper precautions.

How To Safely Remove Mercury Amalgams

If you want to see how mercury should be safely removed, I would recommend watching this video from the IAOMT [11].  This video demonstrates the Safe Mercury Amalgam Removal Technique (SMART) for dentists and patients.  Here is a summary of what is discussed in this video:

1. Each room where amalgams will be removed should have a high volume air filtration system capable of removing mercury vapors and amalgam particles generated during the removal of one or more mercury fillings.  The windows should be opened if possible.

2. The patient should be given a slurry of charcoal, chlorella, or a similar adsorbent to rinse and swallow before the procedure.

3. Protective gowns should be used by the dentist, dental personnel, and the patient because substantial quantities of particles generated will elude collection by suction devices.  These particles can be spread from the patient’s mouth to other parts of the body.

4. A full body and permeable barrier should be used to protect the patient’s clothing.

5. External air or oxygen delivered via a nasal mask for the patient should also be utilized to ensure that the patient doesn’t inhale any mercury vapor or amalgam particulates during the procedure.

6. A saliva ejector should be placed under the dental dam to reduce mercury exposure to the patient.

7. A dental dam should be placed and sealed properly on the patient’s mouth as well as a full head, face, and neck barrier that is under and around the dam.

8. During dental amalgam removal the dentist should utilize an IQ Air Dental Mercury Flex Vac or a similar device in close proximity to the operating field to mitigate mercury exposure.

9. Copious amounts of water to reduce heat and a conventional high speed evacuation device to capture mercury discharges should be used to reduce mercury levels.

10. The amalgam should be sectioned in chunks and removed in as large pieces as possible.

11. Once the removal process is complete, the patient’s mouth should be thoroughly flushed with water, and should then be rinsed out with a slurry of charcoal, chlorella, or a similar adsorbent.

12. An amalgam separator should be installed and used to properly collect mercury amalgam waste so that it is not released into the dental office.

What Alternatives Are There To Silver Fillings?           

Here are four alternatives to silver fillings:

Direct composite fillings are the most common alternative filling, and the main reason for this is because the white color matches the tooth and the cost is reasonable.  And while this is a better option than mercury amalgams, it isn’t without any controversy, as the Bis-GMA resin composite has bisphenol-A (BPA), which is a known endocrine disruptor.  The question is whether or not the levels of BPA is significant, and a 2018 journal article investigated the leaching of BPA from 4 composite filling materials, 3 sealants, and 2 orthodontic bonding materials (10) [12].  The results of the study showed that BPA is released from the dental materials, although the authors stated that the amount of BPA was relatively low.  That being said, low amounts of BPA still might result in endocrine disruption, and so if you need fillings it’s probably best to work with a biological dentist, who hopefully will recommend BPA-free composites.

In summary, 80% of people have more than one mercury amalgam, and while the ADA and other organizations still feel that silver fillings are safe, based on the information presented in this blog post I hope you understand that it’s a good idea to choose an alternative.  While many healthcare practitioners test for levels of heavy metals, in some cases it makes more sense to test for the immune response to mercury, and two tests that have the ability to do this include the Chemical Immune Reactivity Screen by Cyrex Labs, and the MELISA test.  As for its effect on thyroid health, mercury not only can have a direct effect on thyroid hormone levels, but there is evidence that it can play a role in thyroid autoimmunity…especially for those who are allergic or sensitive to mercury.  In a perfect world nobody would have mercury amalgams, but if you currently have one or more of them then I would recommend working with a dentist who takes the proper precautions in removing mercury.