If you’ve been trying to uncover all of the root causes behind your Hashimoto’s condition, you have likely already started looking at problems associated with your gut—either related to your diet and food sensitivities, gut infections, or nutrient deficiencies. But many people don’t realize that the gut extends all the way to the mouth. And in the mouth, there are a number of things that can occur that can be triggers for Hashimoto’s and other autoimmune diseases.
Gum disease (periodontitis), fluoride use, infections in the mouth, dental x-rays, and many dental procedures themselves can all be triggers responsible for your symptoms. This includes procedures like root canals, implants, crowns, and yes, even those typical and seemingly ordinary silver fillings (amalgams) many of us have.
In my survey of 2232 people with Hashimoto’s, 8.25 percent said they had extensive dental work done before they started feeling unwell. Perhaps not an overwhelming percentage, but those responses likely don’t include all of the people who may have just had a lot of fillings over the course of their lifetime. I have found that amalgam fillings can be triggers for many of my clients and readers. Having fillings and dental work during my younger days was also a trigger of my own symptoms.
Many people don’t realize that dental amalgams, often called “silver” fillings, actually contain 50 percent of mercury by weight. A small amount of ongoing mercury exposure comes from mercury vapor outgassing from such fillings. In fact, mercury is released every time a person chews. (I’ve linked a video of this mercury “outgassing” below!)
Mercury exposure can also occur when old fillings fail and need to be replaced. Many of my clients have reported an onset or increase in Hashimoto’s symptoms after improper amalgam removal. Careful protocols need to be followed by your dentist to ensure that you, as well as your dentist, do not have greater exposure to mercury than necessary. In this article, you will learn about:
- The safety concerns with mercury and dental amalgams
- Why some people can be more greatly affected by dental amalgams
- The dental amalgam and Hashimoto’s connection
- How to determine if you need your amalgams removed
- The recommended protocol should you need to have your amalgams removed
- Ongoing dental self-care
Mercury Exposure and Toxicity
Before I talk about dental amalgams, let’s talk about mercury toxicity in general.
According to the World Health Organization (WHO), human exposure to mercury can be caused by the outgassing of mercury from dental amalgams, the ingestion of contaminated fish, or occupational exposure (working with metals or waste products containing metals).
Symptoms of mercury accumulation may include digestive issues, joint pain, fatigue, brain fog/trouble concentrating, and hair loss. Many of the symptoms related to mercury exposure overlap with those seen in Hashimoto’s.
Animal studies have linked mercury toxicity to neurodegenerative diseases. There have also been a series of associations between mercury and neurodegenerative diseases in humans. In addition to the brain, metallic mercury has also been found deposited in the thyroid.
Safety Concerns with Mercury and Dental Amalgams
Most human mercury exposure comes from mercury vapor outgassing from dental amalgam fillings, at a rate of 2 to 28 micrograms per facet surface per day, of which about 80 percent is absorbed.
You can actually watch a video of mercury vapor being released from a human tooth here. Once you view this video, you will understand why gum-chewing isn’t recommended for people with dental amalgams due to the increased mercury vapor outgassing. (BTW — while you’re visiting YouTube, you may also want to subscribe to my channel… my one minute bone broth video is one of the most popular ones so far.)
In 2009, the Environmental Protection Agency (EPA) ruled dental amalgams as a class II (riskier) device and identified specific practices for managing their handling and disposal. That said, the FDA hasn’t yet recommended against the use of amalgams (you can read what the FDA says about dental amalgams here). Other organizations have made steps to actually stop their use and find alternatives.
The WHO has recommended that a phase down approach to dental amalgams should be pursued by promoting disease (and cavity) prevention, as well as alternatives to amalgams. The WHO also outlined the need for more research, higher education of dental professionals, and increased public awareness.
In 2013, the US ratified the Minamata Convention on Mercury, introducing a plan to dramatically reduce mercury in the environment. While this plan doesn’t completely ban the use of mercury in dental amalgams, it does require a “phase-down” approach of the toxic material.
While the American Dental Association (ADA) itself has a toxic substance “protocol” for safe handling of the amalgam mixture once it is prepared by a dentist or assistant, the safety of dental amalgams for patients has yet to be fully addressed.
In fact, there has been recent research that has shown, alarmingly, that some of the new amalgam “blends”, created to be superior in strength and corrosion resistance, actually emit about ten times more mercury vapor than ones used prior to 1970.
Given these obvious concerns about the need to reduce the use of dental amalgams, you might wonder what the research says relating to Hashimoto’s. Are dental amalgams making your Hashimoto’s symptoms worse? Should you remove them in order to improve your antibody levels and overall well-being?
To get to those answers, let’s talk about why some people with Hashimoto’s could be at an even greater risk of mercury toxicity from dental amalgams than others (and how to know if you have mercury sensitivity).
Why Some People Are More Greatly Affected by Dental Amalgams
We’re all biologically unique. Some of us have genetic predispositions that can affect us in regards to disease development. We know that all people with Hashimoto’s have a genetic predisposition for the autoimmune disease, and many have food sensitivities too. Some people with Hashimoto’s have greater sensitivities and reactivity to metals than others.
I have found that mercury sensitivity is a problem for many of my clients, making dental amalgams more of a concern. But not everyone with Hashimoto’s has this hypersensitivity.
So when clients and readers ask me if they should prioritize removing their dental amalgams, the first thing I always want to do is determine if they have mercury sensitivity or not. If they do, dealing with their dental amalgams as a priority can make a lot of sense. If they don’t have mercury sensitivity, removing their amalgams may not be the highest priority for them.
So how do you know if you have mercury sensitivity? You can take a test known as the MELISA (Memory Lymphocyte Immunostimulation Assay) test.
The MELISA test will tell you if your body has an immune reaction to mercury and your silver amalgam fillings. Again, if you have Hashimoto’s and mercury sensitivity, you may want to remove those silver fillings sooner than later.
There have been a few studies that have specifically looked into this. In one study with people who tested positive on the MELISA test and had their mercury amalgams removed, those individuals saw a decrease in thyroid peroxidase and thyroglobulin antibodies. In this same study, those with Hashimoto’s who did not test positive for mercury sensitivity on the MELISA test did not see an improvement when they removed their dental amalgams.
An earlier study focused on patients described as “mercury-allergic with autoimmunity” that had their amalgams removed and replaced with composite (non-mercury) fillings. Seventy-one percent of patients experienced health improvements, and the ones who improved were the ones with the highest lymphocyte reactivity before the amalgam removal.
A study in 2010 looked at the replacement of amalgam in mercury-allergic subjects (as defined with a positive MELISA test). The results? Several laboratory parameters (including thyroid antibodies) were normalized, and there were other reported health improvements in about 70 percent of patients. There were no changes seen in subjects that had been classified as non-allergic who underwent amalgam replacement. There were also no changes seen in mercury-allergic subjects who did not have their amalgams replaced.
Note that in a study done in 2014 looking at the effects of removing dental amalgams in people with Hashimoto’s, but where mercury sensitivity was NOT looked at as a specific test factor, the results showed there was no relation of amalgam with Hashimoto’s. I feel like this study missed the forest for the trees!
The MTHFR Gene Variation
When it comes to the dangers of having dental amalgams, mercury sensitivity is one factor to consider. Another is your body’s ability to clear accumulated toxins, including heavy metals.
Most people with Hashimoto’s already have issues with clearing toxins. But if you have certain genetic variations (called polymorphisms), you can be at an even greater risk. Your body may not be good at detoxifying mercury and may store it like a toxic waste dump in your body.
The MTHFR gene variation is one example of this, as it prevents people from properly methylating (a key detox process in the body). If your body can’t clear toxins such as mercury, you can start seeing symptoms associated with poor methylation, such as irritability, depression, anxiety, and brain fog.
I recommend focusing on your liver to detoxify the body and support the methylation pathways. In my Root Cause survey, 45 percent of people with Hashimoto’s said they felt better after adding methylation-supporting supplements to their regimen.
Note that I am not talking about chelating therapies here. Chelation can actually cause more issues, as the chelation process pulls out the mercury hiding deep in the body and may simply deposit them elsewhere if the liver or gut aren’t functioning optimally. To read more about safer ways to detoxify your body and support the methylation pathways, read my article on liver support.
The Glutathione Transferase (GST) Polymorphism
Another genetic variation that can decrease the body’s ability to clear heavy metals like mercury is a polymorphism of the gene that controls an important detoxifying enzyme that regulates the excretion of mercury. This enzyme is called glutathione-s-transferase (GSST), and the polymorphism is called the glutathione transferase (GST) polymorphism.
How Do You Know if Your Body is Storing Mercury?
Once you test for mercury sensitivity and find out if you have one or more of the genetic variations that can diminish your body’s ability to detoxify itself from heavy metals, you can check how much mercury is currently stored in your body. Tests used to measure mercury levels typically involve samples of blood, urine or hair. The challenge with measuring mercury levels in your body, however, is that different types of measures are only optimal for specific types of mercury. Measurements are also sensitive to the timing of the exposures, so you can get variations in results.
Having said that, you can do a more complex test, called a provoked urine test, which involves taking a chelating agent like DMSA (dimercaptosuccinic acid) or DMPS (dimercaptopropane sulfonate). These chelating agents will bind to the mercury and help to pull it out of the storage cells, for a more accurate reading.
I like the Toxic Metals 24 Hour Urine Collection-Doctor’s Data Kit for home testing without a prescription. However, DMSA and DMPS do require a prescription, and I recommend first discussing the need for any type of mercury testing with your doctor.
Blood tests can also be done to test for mercury, but unless there has been a high acute mercury exposure (one-time/sudden instead of chronic or ongoing), the results can vary widely.
The mercury concentration typically found in whole blood is usually lower than 10 μg/L, but can be as much as 20 μg/L and still be considered normal. With long-term exposure to mercury vapor, the blood’s mercury concentration can rise to 35 μg/L. But again, testing can often show wide fluctuations.
The Dental Amalgam and Hashimoto’s Connection
Along with the earlier studies mentioned that focused on people having documented mercury sensitivities, there have been more general findings showing a connection between dental amalgams (mercury toxicity) and autoimmune disorders, including Hashimoto’s.
First, I want to point out an interesting connection relating to mercury and Hashimoto’s—and that is relating to selenium deficiency.
Mercury can deplete the body of selenium, as well as the antioxidants that require selenium, that work to help us get rid of toxins such as mercury! Selenium is a vital nutrient required in the synthesis of thyroid hormone. Mercury binds to selenium-containing proteins and causes a functional selenium deficiency.
Research has shown that most people with Hashimoto’s will have a deficiency in selenium, and being deficient in this nutrient is a very common and widely recognized trigger of autoimmune thyroid conditions. (You can read more about selenium deficiency here.)
The good news is that supplementing with selenium has been found to reduce thyroid antibodies and thyroid symptoms. When I surveyed my Root Cause readers, 63 percent said that taking a selenium supplement helped them feel better.
Along with creating selenium deficiencies, mercury can act as an endocrine disruptor. Elevated levels of mercury in the body have been found to change the way T4 converts to T3, leading to potentially toxic levels of T4 and suppressed levels of T3. One of the problems is that your thyroid needs some iodine for healthy thyroid hormone synthesis. But because mercury is chemically similar to iodine, your thyroid will absorb and store it as well. When your body stores mercury instead of iodine, it can become deficient in iodine, leading to inadequate levels of T3. (That said, iodine deficiency in Hashimoto’s is uncommon, and you can read about that here.)
There have been studies that have looked further at the rates of mercury in the blood compared to the level of thyroid disease. Associations between positive thyroid antibodies and total blood mercury in women were evaluated in an NHANES study done between 2007 and 2008. They found that mercury exposure was associated with cellular autoimmunity and that mercury does accumulate in the thyroid gland. They also found specifically higher levels of thyroglobulin antibodies in people who had high levels of mercury.
A 2006 forensic study found that the more mercury fillings a person had, the higher amount of mercury was found in their thyroid gland. Mercury levels in the thyroid and in the renal cortex were respectively about 5 and 4 times higher in subjects with 12 occlusal amalgams or more compared with subjects with 3 occlusal amalgams.
Finally, a study found that babies of women with amalgam fillings may also have mercury deposits in their organs and experience an impact on thyroid function. The higher the maternal levels of mercury in the blood, the higher the TSH levels in the children.
How to Determine if You Need Your Amalgams Removed
So that’s a lot of information! Where should you go from here?
First, I suggest you consult with a biological dentist. Biological dentistry is a branch of dentistry that focuses on the connection between oral care and the health status of the rest of the body. It is very prevention-oriented, and biological dentists try to prevent health problems that may originate from exposure to certain procedures and materials used during dental care.
To find a biological dentist in your area, visit the International Academy of Oral Medicine & Toxicology’s website for a listing. Even if you have no existing amalgams, you may want to find a biological dentist and have an evaluation for preventative purposes.
Should you have a question concerning existing amalgams, he or she will likely have you take the MELISA test to check for mercury sensitivity. You can then make an informed decision as to whether you should prioritize having any amalgams removed. The number of amalgams you have may be a decision factor. A biological dentist will work with you on future filling needs, as well as providing other preventative information and procedures.
There is another test your biological dentist may recommend called the Clifford Materials Reactivity Test. This test helps identify the body’s response to almost one hundred chemical groups that may be used in medical or dental treatments. It also provides info on the body’s response to corrosion byproducts of these materials, which is particularly important as materials break down in the mouth.
(Update: As of December 2020, Clifford Materials Reactivity Testing is no longer available, and I am unaware of alternative options at this time. However, your biologist dentist may be familiar with similar tests that are available — please consult with your biologist dentist for guidance.)
Should you decide to have amalgams removed, there is a recommended protocol that your dentist should use. There are slightly different variations available from different organizations, but I like the protocol that has been developed by The Institute for Functional Medicine (IFM), as it is very thorough and supportive. The protocol consists of a pre-procedure regimen (7 days), requirements for the actual day of treatment, and a post-procedure regimen (2 weeks). It also assumes you are working with a biological dentist who is taking other procedural precautions.
The Recommended Protocol, Should You Need to Have Your Amalgams Removed
Again, if you determine you should have your amalgam fillings removed, it’s important to do it safely. If done improperly, you may breathe in potentially large doses of mercury vapor or other toxic dental chemicals during the process. This can be particularly impactful if you have the MTHFR gene mutation and intestinal permeability, as the mercury overload can overburden your already weakened detox pathways.
Many of my clients have found that they have an onset or increase in Hashimoto’s symptoms after improper amalgam removal. Proper precautions for safe removal of dental amalgams (to prevent the absorption of mercury vapor into your body) include:
- A Pre-Procedure Assessment: Lab tests done one week prior to the procedure to ensure fitness for the procedure include a complete blood count (CBC), a comprehensive metabolic panel (CMP) and a renal function-glomerular filtration rate (GFR) test.
- A Pre-Procedure Regimen (for 7 days prior to the procedure): This includes specific doses of vitamin C, either liposomal glutathione (note: contains soy) or N-Acetyl-Cysteine (NAC), B-complex vitamins, CoQ-10, selenium, vitamin E, magnesium, and lots of water.
- Dental Procedure Day and Post-Procedure Regimen (2 weeks following the procedure): There will be a variety of preventative measures your dentist will want you to take, such as rinsing your mouth with activated charcoal several times before and after the procedure (to help bind any ingested mercury). They will also have you swish your mouth with chlorella to help bind and prevent any mercury absorption.
During the procedure, a biological dentist will likely include many of the IFM’s recommended protocols for safe amalgam removal, including: rubber dams that cover your mouth, oxygen masks and skin covers (for you), a saliva ejector under the dam, eye protection (for you), auxiliary suction devices that have mercury filters for escaping mercury vapor, and more. The dentist and dental assistant will also have special masks and gloves to reduce their exposure. There are recommended methods that the dentist will follow as well to minimize the amount of potential mercury exposure.
You will most likely be instructed to continue taking the glutathione (liposomal), NAC or other liver support supplements. Additionally, you may be told to continue with your other vitamins and supplements. Some dentists may want to give you an intravenous (IV) of either vitamin C or additional nutrients.
Note that beyond these IFM protocols, the Liver Support, Adrenal Support, and Gut Balance protocols found in my Hashimoto’s Protocol book may be beneficial prior to starting the dentist’s pre-procedure assessments. This can help to strengthen the body, to ensure safe and effective detoxification.
For those with the MTHFR gene variation, there are additional supplements, like Rootcology’s MTHFR Pathways, that may be helpful in supporting the detoxification pathways.
If you’ve already had amalgams removed without taking these types of precautions, there are many things you can still do to minimize any toxic effects. I would again recommend that you go through the fundamental protocols in my book (liver, adrenals, and gut), as well as work with your doctor to test for any residual heavy metals in your body via a heavy metal-provoked urine challenge. The results can help determine if you need any additional interventions.
You can read about my colleague Carrie Vitt’s own experience absorbing heavy metals from her amalgam removal. This is an example of how a “backed up” liver meant the heavy metals couldn’t properly filter from her body. With a bit of prevention and care, you can ensure this won’t happen to you.
If you are deferring having your amalgams removed (perhaps you were negative on the mercury sensitivity MELISA test or you have other issues your doctor feels need to be addressed as a priority), I recommend taking some special preventative precautions in the meantime. These are actually important for anyone with Hashimoto’s. A little self-care can go a long way in keeping you feeling well.
Ongoing Dental Self-Care
Getting a biological dentist is a great initial step. Questions to ask when finding a new dentist include:
- Do you have your patients take the MELISA test?
- Do you follow the IFM’s recommended procedures for removing mercury fillings?
- Do you offer tests similar to the Clifford Materials Reactivity Test?
- Do you use a thyroid shield for dental X-rays?
There are many possible dental triggers for Hashimoto’s, including periodontitis, mouth infections, and dental procedures themselves. It’s important to find a biological dentist who can help you identify possible issues and address them in a way that will protect your thyroid health.
Should you have amalgams, the first thing you can do with your new dentist is get the MELISA test so that you know if their removal is a priority for you.
You may also want to start taking selenium if you don’t already. As mentioned earlier, mercury can cause selenium deficiency, which affects thyroid hormone synthesis. Many people with Hashimoto’s feel better when taking therapeutic dosages of selenium, and it has been shown to also reduce thyroid antibodies.
Another thing you can start today is to think about your dental health timeline. Just like I always recommend people document their own health history (symptoms, health issues, infections, etc.), I also suggest people get a handle on their dental health history. Note all of the dental procedures you’ve had (abscesses, dental surgeries, dental X-rays, fluoridation procedures, infections in the mouth and gums, root canal, crowns, amalgam fillings, etc.).
Also, focus in on the self-care you give your teeth! Do you floss? (If you don’t, you are more prone to gum inflammation and infections!) Do you regularly have dental checkups? (If you don’t, you are more prone to having issues.) Do you use fluoridated toothpaste? Do you eat a sugary/carb-heavy diet? All of these can be possible triggers of Hashimoto’s and other autoimmune conditions. You may find out, like Carrie did, that dental work is a trigger that has worsened your symptoms. You can download my free health timeline sample to use as inspiration to document your health journey and note when you started feeling unwell.
Finally, there are many self-care steps for improved dental health discussed towards the end of this article. Additionally, I discuss my recommended dental protocol in greater detail in my book, Hashimoto’s Protocol. All of my suggested protocols, including liver and gut support (remember, the mouth is an extension of the gut!), can also be found in the book. These protocols will support your liver and heavy metal detoxification, which are important for healing your thyroid and serve as a proactive measure to prevent further damage.
Having dental amalgams can put you at risk of having high mercury levels and symptoms of mercury toxicity, many of which overlap with thyroid disease. Certain people with Hashimoto’s have been found to have a genetic hypersensitivity to metals and environmental toxins, and in those people, the removal of amalgams has been shown to help reduce thyroid antibodies. The MELISA test can be taken to ascertain if one has this sensitivity and is therefore more prone to having issues with mercury accumulation.
If you decide that amalgam removal is a priority for you, you can work with your biological dentist and find alternatives to amalgams for any future fillings. There are a number of restorative materials to work with, including resin composite, glass ionomer, resin ionomer, porcelain and gold alloys. The important thing is that you take a step towards greater oral care today, knowing it can and does have an impact on your thyroid and how you feel!
I hope this helps you on your health journey!
P.S. You can download a free Thyroid Diet Guide, 10 thyroid-friendly recipes, and the Nutrient Depletions and Digestion chapter for free by going to www.thyroidpharmacist.com/gift. You will also receive occasional updates about new research, resources, giveaways and helpful information.
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- Bernhoft RA. Mercury Toxicity and Treatment: A Review of the Literature. Journal of Environmental and Public Health. 2012;2012:460508. doi:10.1155/2012/460508.
- Elli L, Rossi V, Conte D, et al. Increased Mercury Levels in Patients with Celiac Disease following a Gluten-Free Regimen. Gastroenterology Research and Practice. 2015;Article ID 953042. Doi:10.1155/2015/953042.
- Food and Drug Administration. Dental Devices: Classification of Dental Amalgam, Reclassification of Dental Mercury, Designation of Special Controls for Dental Amalgam, Mercury, and Amalgam Alloy. https://www.fda.gov/downloads/MedicalDevices/ProductsandMedicalProcedures/DentalProducts/DentalAmalgam/UCM174024.pdf. Accessed October 16, 2018.
- United States Environmental Protection Agency. Mercury in Dental Amalgam. EPA. https://www.epa.gov/mercury/mercury-dental-amalgam#amalgamwaste. Accessed October 16, 2018.
- Center for Scientific Information – ADA Science Institute. Amalgam Separators and Waste Best Management. https://www.ada.org/en/member-center/oral-health-topics/amalgam-separators. American Dental Association. Published October 12, 2017. Accessed October 16, 2018.
- World Health Organization. Mercury and health. http://www.who.int/news-room/fact-sheets/detail/mercury-and-health. WHO. Published March 31, 2017. Accessed October 16, 2018.
- Bengtsson UG, Hylander LD. Increased mercury emissions from modern dental amalgams. Biometals. 2017;30(2):277-283. doi:10.1007/s10534-017-0004-3.
- Sterzl l, Prochazkova J, Hrda P, et al. Removal of dental amalgam decreases anti-TPO and anti-Tg autoantibodies in patients with autoimmune thyroiditis. Neuro Endocrinol Lett. 2006 Dec;27 Suppl 1:25-30.
- Prochazkova J, Sterzl I, Kucerova H, et al. The beneficial effect of amalgam replacement on health in patients with autoimmunity. Neuro Endocrinol Lett. 2004 Jun;25(3):211-8.
- Hybenova M, Hrda P, Prochazkova J, et al. The role of environmental factors in autoimmune thyroiditis. Neuro Endocrinol Lett. 2010;31(3):283-9.
- Kisakol G. Dental amalgam implantation and thyroid autoimmunity. Bratisl Lek Listy. 2014;115(1):22-4.
- Ye B-J, Kim B-G, Jeon M-J, et al. Evaluation of mercury exposure level, clinical diagnosis and treatment for mercury intoxication. Annals of Occupational and Environmental Medicine. 2016;28:5. doi:10.1186/s40557-015-0086-8.
- Klaassen C, Casarett L, Doull J. Casarett and Doull’s toxicology: the basic science of poisons. New York, NY: McGraw-Hill Education; 2013.
- Spiller H. Rethinking mercury: the role of selenium in the pathophysiology of mercury toxicity. Clin Toxicol. 2017 Nov 10;1-14. doi:10.1080/15563650.2017.1400555
- Gallagher CM, Meliker JR. Mercury and thyroid autoantibodies in U.S. women, NHANES 20007-2008. Environ Int. 2012 Apr;40-39-43. doi:10.1016/j.envint.2011.11.014.
- Guzzi G, Grandi M, Cattaneo C, et al. Dental amalgam and mercury levels in autopsy tissues: food for thought. Am J Forensic Med Pathol. 2006 Mar;27(1):42-5.
- Ursinyova M, Uhnakova I, Serbin R, et al. The relation between human exposure to mercury and thyroid hormone status. Biol Trace Elem Res. 2012 Sep;148(3):281-91. doi:10.1007/s12011-012-9382-0.