According to FDA 2020 Guidelines

Based on FDA recommendations released in September 2020, over 85% of the US population is at risk for adverse reactions from mercury exposure created by dental amalgam fillings.1 If it is dangerous for this large of a segment of the population, why are we considering using them for anyone?

People with Neurological Diseases (17%): In a systematic analysis of the Global Burden of Disease (GBD) 2017 study published in JAMA, data on incidence, prevalence, mortality, and disability-adjusted life-years of major neurological disorders in the US were derived. Approximately 1 in 6 adults were estimated to have neurological disease. Fourteen major neurological disorders were analyzed including stroke, Alzheimer disease and other dementias, Parkinson disease, epilepsy, multiple sclerosis, motor neuron disease, migraine, tension-type headache, traumatic brain injury, spinal cord injuries, brain and other nervous system cancers, meningitis, encephalitis, and tetanus.2

Sensitivity/Allergy to Mercury (12%): This population includes individuals with documented hypersensitivity or allergy to mercury, which can manifest in various symptoms. Research indicates that sensitivity among the general population varies, with certain demographics, especially those with specific health conditions, exhibiting a higher risk upon mercury exposure.3,4

Kidney Disease (14%): Individuals with kidney disease are at a higher risk due to their compromised ability to excrete heavy metals like mercury. Studies have shown a significant correlation between dental amalgam exposure and elevated mercury levels in urine among children and adults with kidney impairment.5,6 The prevalence of kidney disease in the U.S. is around 14%.7

Women of Child-Bearing Age (20%): Women of child-bearing age, especially pregnant women, are particularly vulnerable to the effects of mercury. Research links amalgam exposure to adverse pregnancy outcomes, leading this population to be advised to limit mercury exposure to safeguard fetal development.8–16 One important issue to keep in mind is that the rate of unintended pregnancies is high and therefore occur in women who aren’t prepared or thinking about protections for themselves and their unborn children17,18. Given the current landscape wherein 12 states have a total abortion ban and 29 states have abortion bans based on gestational duration,19,20 more children will be born to younger women and this will have greater effects in women with lower socio-demographic backgrounds.

Children (24%): Children represent a high-risk group for mercury toxicity due to their developing nervous systems.9,16,21 Studies have shown a direct relationship between the number of amalgam fillings in children and levels of mercury in their blood and urine.6 The prevalence of amalgam restorations in permanent teeth ranged from 4.1% among those aged 6 through 11 years to 15.3% among those aged 12 through 15 years and 22.8% among those aged 16 through 19 years.22

Overlap between one or more of these conditions would add significant burden to anyone who belongs to one of the categories listed. For example, individuals suffering from neurological diseases may exhibit increased sensitivity due to their conditions. Children with kidney disease are particularly vulnerable to heavy metal toxicity due to mercury in dental fillings. Women who are pregnant or breastfeeding who also have another one of the FDA-identified risks would have compounded risk. There may also be an intersecting category of individuals with all risk factors: children with neurological diseases, who are sensitive to mercury and have kidney issues, potentially more common in low-income backgrounds where amalgam dental fillings are used almost exclusively.

1. US Food and Drug Administration C for D and R. Dental Amalgam Fillings [Internet]. FDA. FDA; 2023 [cited 2025 Apr 30]. Available from: https://www.fda.gov/medical-devices/dental-devices/dental-amalgam-fillings

2. GBD 2017 US Neurological Disorders Collaborators, Feigin VL, Vos T, Alahdab F, Amit AML, Bärnighausen TW, et al. Burden of Neurological Disorders Across the US From 1990-2017: A Global Burden of Disease Study. JAMA Neurol. 2021 Feb 1;78(2):165–76.

3. Park SB, Kim EK, Sakong J, Park EY. Association between dental amalgam restoration and urine mercury concentrations among young women: a cross-sectional study. J Yeungnam Med Sci. 2023 Oct;40(4):373–80.

4. Kall J, Just A, Aschner M. What Is the Risk? Dental Amalgam, Mercury Exposure, and Human Health Risks Throughout the Life Span. In: Hollar D, editor. Epigenetics, the Environment, and Children’s Health Across Lifespans [Internet]. Cham: Springer International Publishing; 2016 [cited 2025 Apr 21]. p. 159–206. Available from: https://doi.org/10.1007/978-3-319-25325-1_7

5. Dalkiran T, Carman KB, Unsal V, Belge Kurutas E, Kandur Y, Dilber C. Evaluation of oxidative stress biomarkers in acute mercury intoxication. Folia Med (Plovdiv). 2021 Oct 31;63(5):704–9.

6. Baek HJ, Kim EK, Lee SG, Jeong SH, Sakong J, Merchant AT, et al. Dental amalgam exposure can elevate urinary mercury concentrations in children. Int Dent J. 2016 Jun;66:136–43.

7. CDC. Chronic Kidney Disease in the United States, 2023 [Internet]. Chronic Kidney Disease. 2024 [cited 2025 Apr 30]. Available from: https://www.cdc.gov/kidney-disease/php/data-research/index.html

8. El-Badry A, Rezk M, El-Sayed H. Mercury-induced Oxidative Stress May Adversely Affect Pregnancy Outcome among Dental Staff: A Cohort Study. Int J Occup Environ Med (The IJOEM) [Internet]. 2018 Jul 8 [cited 2019 Sep 10];9(3 July):1181-113–9. Available from: https://www.theijoem.com/ijoem/index.php/ijoem/article/view/1181

9. Escalante E, Semenova Y, Peana M, Bjørklund G. The Impact of Mercury from Dental Amalgams on Pregnancy and Childhood: A Health and Risk Assessment Evaluation. Curr Med Chem. 2025 Jan 28;

10. Heidam LZ. Spontaneous abortions among dental assistants, factory workers, painters, and gardening workers: a follow up study. J Epidemiol Community Health [Internet]. 1984 Jun [cited 2018 Apr 30];38(2):149–55. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1052339/

11. Mortazavi SM, Mortazavi G, Paknahad M. Mercury transmitted from mother’s with amalgam dental fillings to fetus. J Matern Fetal Neonatal Med. 2017 Mar;30:594.

12. Movassagh H, Halchenko Y, Sampath V, Nygaard UC, Jackson B, Robbins D, et al. Maternal gestational mercury exposure in relation to cord blood T cell alterations and placental gene expression signatures. Environ Res [Internet]. 2021 Oct [cited 2025 Apr 23];201:111385. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8478717/

13. Sakamoto M, Itai T, Murata K. Effects of Prenatal Methylmercury Exposure: From Minamata Disease to Environmental Health Studies. Nihon Eiseigaku Zasshi. 2017;72(3):140–8.

14. Yoshimasu K, Kiyohara C, Takemura S, Nakai K. A meta-analysis of the evidence on the impact of prenatal and early infancy exposures to mercury on autism and attention deficit/hyperactivity disorder in the childhood. Neurotoxicology. 2014 Sep;44:121–31.

15. Bjørklund G, Chirumbolo S, Dadar M, Pivina L, Lindh U, Butnariu M, et al. Mercury exposure and its effects on fertility and pregnancy outcome. Basic Clin Pharmacol Toxicol. 2019 Oct;125(4):317–27.

16. Björkman L, Lygre GB, Haug K, Skjærven R. Perinatal death and exposure to dental amalgam fillings during pregnancy in the population-based MoBa cohort. PLoS One. 2018;13(12):e0208803.

17. Kantorová V. Unintended pregnancy and abortion: what does it tell us about reproductive health and autonomy? Lancet Glob Health [Internet]. 2020 Sep [cited 2025 Apr 30];8(9):e1106–7. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7375788/

18. Bearak J, Popinchalk A, Alkema L, Sedgh G. Global, regional, and subregional trends in unintended pregnancy and its outcomes from 1990 to 2014: estimates from a Bayesian hierarchical model. Lancet Glob Health [Internet]. 2018 Apr [cited 2021 Apr 30];6(4):e380–9. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6055480/

19. Cole AC Devan. Abortion law state map: See where abortions are legal or banned [Internet]. CNN. 2025 [cited 2025 May 2]. Available from: https://www.cnn.com/us/abortion-access-restrictions-bans-us-dg

20. The Guttmacher Institute. State Bans on Abortion Throughout Pregnancy | Guttmacher Institute [Internet]. 2025 [cited 2025 May 2]. Available from: https://www.guttmacher.org/state-policy/explore/state-policies-abortion-bans

21. Golding J, Gregory S, Emond A, Iles-Caven Y, Hibbeln J, Taylor CM. Prenatal mercury exposure and offspring behaviour in childhood and adolescence. Neurotoxicology. 2016;57:87–94.

22. Beltrán-Aguilar ED, Thornton-Evans G, Wei L, Bernal J. Prevalence and mean number of teeth with amalgam and nonamalgam restorations, United States, 2015 through 2018. J Am Dent Assoc [Internet]. 2023 May [cited 2025 Apr 30];154(5):417–26. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10985832/