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There is considerable concern among scientists and the public about the hormone-mimicking properties of many chemical components of plastics, including those found in dental composites. The commonly used Bis-GMA resin uses one of the most controversial of these, Bisphenol-A (BPA).


Responsible composite manufacturers claim that there is no unreacted BPA in dental resins, and that it takes high temperatures – several hundred degrees – to liberate free BPA. Other critics say that, in fact, the ester bonds in resins are subject to hydrolysis, and BPA can be liberated in measurable quantities. We know that dental sealants can vary in the amount of BPA they leak, but at present there is no good in vitro survey of how much BPA is liberated by the major brands of composite resins. Also, we know that the world is full of plastic chemicals, and every living thing on earth has a measurable tissue level of BPA. We don’t really know if the amount of BPA released from dental composite is enough to raise a person’s exposure above the environmental background level, or if it is truly insignificant. The accompanying articles spell out the range of issues under investigation.

Fluoride and Lower IQ

Sources of human exposure to fluoride have drastically increased since community water fluoridation began in the U.S. in the 1940’s. In addition to water, these sources now include food, air, soil, pesticides, fertilizers, dental products used at home and in the dental office, pharmaceutical drugs, cookware (non-stick Teflon), and an array of other consumer items used on a regular basis. Most people are not aware of important fluoride facts about these sources.

Exposure to fluoride is suspected of impacting nearly every part of the human body, and the potential for harm has been clearly established in scientific research. A 2006 report by the National Research Council (NRC) identified a few health risks associated with fluoride exposure. Susceptible subpopulations, such as infants, children, and individuals with diabetes or renal or thyroid problems, are known to be more severely impacted by intake of fluoride.


Since such populations and all people can potentially be impacted by fluoride exposure, consumers need to know these crucial fluoride facts.


Given the current levels of exposure, to promote overall health, policies should reduce and work toward eliminating avoidable sources of fluoride, including water fluoridation, fluoride-containing dental materials, and other fluoridated products.

Mercury Amalgam Fillings and their Danger to Human Health

Millions of dentists around the world routinely use dental amalgam as a filling material in decayed teeth. Often referred to as “silver fillings”, all dental amalgams actually consist of 45-55% metallic mercury. Mercury is a known neurotoxin that can cause harm to humans, especially children, pregnant women, and fetuses. A 2005 World Health Organization (WHO) report warned of mercury: “It may cause harmful effects to the nervous, digestive, respiratory, immune systems and to the kidneys, besides causing lung damage. Adverse health effects from mercury exposure can be: tremors, impaired vision and hearing, paralysis, insomnia, emotional instability, developmental deficits during fetal development, and attention deficit and developmental delays during childhood. Recent studies suggest that mercury may have no threshold below which some adverse effects do not occur.”

There is a global effort spearheaded by the United Nations Environment Programme to reduce mercury usage, including that of dental mercury, and some countries have already banned its use. However, amalgams are still used for about 45% of all direct dental restorations worldwide, including in the United States. In fact, it has been estimated that there are currently over 1,000 tons of mercury in the mouths of Americans, which is more than half of all the mercury being used in the U.S. today. Reports and research are consistent that these mercury-containing fillings emit mercury vapors, and while these restorations are commonly referred to as “silver fillings”, “dental amalgam”, and/or “amalgam fillings”,  the public is often unaware that amalgam refers to the combination of other metals with mercury. The articles on this page address the health consequences of mercury exposure.

Dental Composites

McCracken, Michael S., Valeria V. Gordan, Mark S. Litaker, Ellen Funkhouser, Jeffrey L. Fellows, Douglass G. Shamp, Vibeke Qvist, Jeffrey S. Meral, and Gregg H. Gilbert. A 24-month evaluation of amalgam and resin-based composite restorations: Findings from The National Dental Practice-Based Research Network. The Journal of the American Dental Association 144, no. 6 (2013): 583-593.

Opdam, N. J. M., F. H. Van de Sande, Ewald Bronkhorst, M. S. Cenci, P. Bottenberg, U. Pallesen, P. Gaengler, Anders Lindberg, M. C. D. N. J. M. Huysmans, and J. W. Van Dijken. Longevity of posterior composite restorations: a systematic review and meta-analysis. Journal of dental research 93, no. 10 (2014): 943-949.


Pallesen U, van Dijken JW. A randomized controlled 30 years follow up of three conventional resin composites in Class II restorations. Dental Materials. 2015; 31(10):1232-44.  


Olea, Nicolás, Rosa Pulgar, Pilar Pérez, Fátima Olea-Serrano, Ana Rivas, Arantzazu Novillo-Fertrell, Vicente Pedraza, Ana M. Soto, and Carlos Sonnenschein. Estrogenicity of resin-based composites and sealants used in dentistry. Environmental health perspectives 104, no. 3 (1996): 298.

Pulgar, Rosa, M. Fatima Olea-Serrano, Arancha Novillo-Fertrell, Ana Rivas, Patricia Pazos, Vicente Pedraza, Jose-Manuel Navajas, and Nicolas Olea. Determination of bisphenol A and related aromatic compounds released from bis-GMA-based composites and sealants by high performance liquid chromatography. Environmental health perspectives108, no. 1 (2000): 21.

Dental Foci, Oral Galvanicity and Interference Fields

Vizkelety, Josef. The role of dental field of disturbances (foci) in systemic cancer formation: myth or fact? (2018).


Vizkelety, Josef, Oettmeier, Ralf, and Alpstein Clinic Team (Gais (AR), Switzerland). Toxins, Foci, Interfering fields, teeth – importance and integration into the concept – What is essential? (2018).

Periodontal Disease and Systemic Diseases

Amar S, Han X. The impact of periodontal infection on systemic diseases. Med Sci Monit.2003;9:RA291–9.


Balakesavan, Prashanth, Sneha R. Gokhale, Vijay Deshmukh, and Ray C. Williams. Periodontal disease and overall health: An update. European Journal of General Dentistry 2, no. 2 (2013): 102.

Friedewald, Vincent E., Kenneth S. Kornman, James D. Beck, Robert Genco, Allison Goldfine, Peter Libby, Steven Offenbacher, Paul M. Ridker, Thomas E. Van Dyke, and William C. Roberts. The American Journal of Cardiology and Journal of Periodontology editors' consensus: periodontitis and atherosclerotic cardiovascular disease. Journal of periodontology 80, no. 7 (2009): 1021-1032.


Humphrey, Linda L., Rongwei Fu, David I. Buckley, Michele Freeman, and Mark Helfand. Periodontal disease and coronary heart disease incidence: a systematic review and meta-analysis. Journal of general internal medicine 23, no. 12 (2008): 2079.


Khanna, Sunali Sundeep, Prita A. Dhaimade, and Shalini Malhotra. Oral health status and fertility treatment including IVF. The Journal of Obstetrics and Gynecology of India 67, no. 6 (2017): 400-404.


Kim, Jemin, and Salomon Amar. Periodontal disease and systemic conditions: a bidirectional relationship. Odontology94, no. 1 (2006): 10-21.

Kinane, D. F., and G. J. Marshall. Peridonatal manifestations of systemic disease. Australian dental journal 46, no. 1 (2001): 2-12.

Meyer, Mara S., et al. A review of the relationship between tooth loss, periodontal disease, and cancer. Cancer Causes & Control 19.9 (2008): 895-907.


Odell, James. Oral Microbiome Toxins and Systemic Diseases.

Seymour, G. J., P. J. Ford, M. P. Cullinan, S. Leishman, and K. Yamazaki. Relationship between periodontal infections and systemic disease. Clinical Microbiology and Infection 13 (2007): 3-10.

Söder B, Yakob M, Meurman JH, Andersson LC, Klinge B, Söder PÖ. Periodontal disease may associate with breast cancer. Breast Cancer Res Treat. 2011;127:497–502.


Yao, Suellen Go, and James Burke Fine. A Possible Link Between Periodontitis & Cancer: A Review.

The Oral Microbiome

Asikainen S, Alaluusua S. Bacteriology of dental infections. (1993) Eur Heart J.;14:43–50.


Curatola Gerald P., (2013). Oral Microbiome Homeostasis: The New Frontier in Oral Care Therapies. J Dent Oral Disord Ther, 1(1), 3. 

Dewhirst FE, Chen T, Izard J et al (2010). The human oral microbiome. J Bacteriol. 192: 5002–5017.

Gao, L., Xu, T., Huang, G., Jiang, S., Gu, Y., Chen, F. Oral microbiomes: more and more importance in oral cavity and whole body. Protein Cell. 2018 May; 9(5): 488–500. Published online 2018 May 7. doi: 10.1007/s13238-018-0548-1.


Mager, D. L., A. D. Haffajee, P. M. Devlin, C. M. Norris, M. R. Posner, and J. M. Goodson. The salivary microbiota as a diagnostic indicator of oral cancer: a descriptive, non-randomized study of cancer-free and oral squamous cell carcinoma subjects. Journal of translational medicine 3, no. 1 (2005): 27.

Michaud, Dominique S., Jacques Izard, Charlotte S. Wilhelm-Benartzi, Doo-Ho You, Verena A. Grote, Anne Tjønneland, Christina C. Dahm et al. Plasma antibodies to oral bacteria and risk of pancreatic cancer in a large European prospective cohort study. Gut 62, no. 12 (2013): 1764-1770.

Meurman JH, Uittamo J. Oral micro-organisms in the etiology of cancer. Acta Odontol Scand. 2008; 66(6):321-6.


Rôças, I. N., and J. F. Siqueira. Root canal microbiota of teeth with chronic apical periodontitis. Journal of clinical microbiology 46.11 (2008): 3599-3606.

Rôças, Isabela N., et al. Denaturing gradient gel electrophoresis analysis of bacterial communities associated with failed endodontic treatment. Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology, and Endodontology 98.6 (2004): 741-749.

Wade, William G.
The oral microbiome in health and disease. Pharmacological research 69, no. 1 (2013): 137-143.


Whitmore, Sarah E., and Richard J. Lamont. Oral bacteria and cancer. PLoS pathogens 10, no. 3 (2014): e1003933.


Zarco, M. F., T. J. Vess, and G. S. Ginsburg. The oral microbiome in health and disease and the potential impact on personalized dental medicine. Oral diseases 18, no. 2 (2012): 109-120.

Zaura, Egija, Jessica E. Koopman, M. Fernandez y Mostajo, and Wim Crielaard. The oral microbiome. Marchesi JR. The human microbiota and microbiome (2014): 20-31.

Fluoride and Lower IQ

Green, Rivka, Bruce Lanphear, Richard Hornung, David Flora, E. Angeles Martinez-Mier, Raichel Neufeld, Pierre Ayotte, Gina Muckle, and Christine Till. Association between maternal fluoride exposure during pregnancy and IQ scores in offspring in Canada. JAMA pediatrics (2019).  

Bashash, Morteza, Deena Thomas, Howard Hu, E. Angeles Martinez-Mier, Brisa N. Sanchez, Niladri Basu, Karen E. Peterson et al. Prenatal fluoride exposure and cognitive outcomes in children at 4 and 6–12 years of age in Mexico. Environmental health perspectives 125, no. 9 (2017): 097017.  

Bashash, Morteza, Maelle Marchand, Howard Hu, Christine Till, E. Angeles Martinez-Mier, Brisa N. Sanchez, Niladri Basu et al. Prenatal fluoride exposure and attention deficit hyperactivity disorder (ADHD) symptoms in children at 6–12 years of age in Mexico City. Environment international 121 (2018): 658-666.   


Choi, Anna L., Ying Zhang, Guifan Sun, David C. Bellinger, Kanglin Wang, Xiao Jing Yang, Jin Shu Li, Quanmei Zheng, Yuanli Fu, and Philippe Grandjean. Association of lifetime exposure to fluoride and cognitive functions in Chinese children: a pilot study. Neurotoxicology and teratology 47 (2015): 96-101.  

Jiménez, L. Valdez, OD López Guzmán, M. Cervantes Flores, R. Costilla-Salazar, J. Calderón Hernández, Y. Alcaraz Contreras, and D. O. Rocha-Amador. In utero exposure to fluoride and cognitive development delay in infants. Neurotoxicology 59 (2017): 65-70. 

Lu, Y., Z. R. Sun, L. N. Wu, X. Wang, W. Lu, and S. S. Liu. Effect of high-fluoride water on intelligence in children. Fluoride 33, no. 2 (2000): 74-78.

Tang, Qin-qing, Jun Du, Heng-hui Ma, Shao-jun Jiang, and Xiao-jun Zhou. Fluoride and children’s intelligence: a meta-analysis. Biological trace element research 126, no. 1-3 (2008): 115-120.

Poureslami, Hamid Reza, Azadeh Horri, and Behshid Garrusi. A comparative study of the IQ of children age 7–9 in a high and a low fluoride water city in Iran. Fluoride 44, no. 3 (2011): 163-7.

Trivedi, M. H., R. J. Verma, N. J. Chinoy, R. S. Patel, and N. G. Sathawara. Effect of high fluoride water on intelligence of school children in India. Fluoride 40, no. 3 (2007): 178-183.

Xiang, Q., Y. Liang, L. Chen, C. Wang, B. Chen, X. Chen, M. Zhou, and P. R. Shanghai. Effect of fluoride in drinking water on children's intelligence. Fluoride 36, no. 2 (2003): 84-94.

Ding, Yunpeng, Huixin Sun, Hepeng Han, Wei Wang, Xiaohong Ji, Xuehui Liu, and Dianjun Sun. The relationships between low levels of urine fluoride on children's intelligence, dental fluorosis in endemic fluorosis areas in Hulunbuir, Inner Mongolia, China. Journal of hazardous materials 186, no. 2-3 (2011): 1942-1946.

Fluorosis and Fluoride Neurotoxicity

Aghapour, Saba, Bijan Bina, Mohammad Javad Tarrahi, Fahimeh Amiri, and Afshin Ebrahimi. Distribution and health risk assessment of natural fluoride of drinking groundwater resources of Isfahan, Iran, using GIS. Environmental monitoring and assessment 190, no. 3 (2018): 137.

Chavoshi, E., M. Afyuni, M. A. Hajabbasi, A. H. Khoshgoftarmanesh, K. C. Abbaspour, H. Shariatmadari, and N. Mirghafari. Health risk assessment of fluoride exposure in soil, plants, and water at Isfahan, Iran. Human and ecological risk assessment 17, no. 2 (2011): 414-430.


DenBesten, Pamela, and Wu Li. Chronic fluoride toxicity: dental fluorosis. In Fluoride and the oral environment, vol. 22, pp. 81-96. Karger Publishers, 2011.

Fallahzadeh, Reza Ali, Mohammad Miri, Mahmoud Taghavi, Abdolmajid Gholizadeh, Ramin Anbarani, Ahmad Hosseini-Bandegharaei, Margherita Ferrante, and Gea Oliveri Conti. Spatial variation and probabilistic risk assessment of exposure to fluoride in drinking water. Food and Chemical Toxicology 113 (2018): 314-321.

Kazi, Tasneem Gul, Kapil Dev Brahman, Hassan Imran Afridi, Faheem Shah, and Mohammad Balal Arain. Effects of high fluoride content in livestock drinking water on milk samples of different cattle in endemic area of Pakistan: risk assessment for children. Environmental Science and Pollution Research(2018): 1-6.


Shashi, A. Histopathological investigation of fluoride-induced neurotoxicity in rabbits. Fluoride 36, no. 2 (2003): 95-105.

Viswanathan, Gopalan. Contribution of Infant Formula and Tea on Daily Fluoride Intake and Prevalence of Fluorosis Among Infants and Children. Food Quality: Balancing Health and Disease 13 (2018): 339.

Mercury Amalgam Fillings and their Danger to Human Health

Attar AM, Kharkhaneh A, Etemadifar M, Keyhanian K, Davoudi V, Saadatnia M. Serum mercury level and multiple sclerosis. Biological Trace Element Research. 2012 May 1;146(2):150-3.

Bartova J, Prochazkova J, Kratka Z, Benetkova K, Venclikova C, Sterzl I. Dental amalgam as one of the risk factors in autoimmune disease. Neuro Endocrinol Lett. 2003; 24(1-2): 65-67. 


Bates, Michael N., Jackie Fawcett, Nick Garrett, Terry Cutress, and Tord Kjellstrom. Health effects of dental amalgam exposure: a retrospective cohort study. International Journal of Epidemiology 33, no. 4 (2004): 894-902.

Bangsi, Dieudonné, Parviz Ghadirian, Slobodan Ducic, Richard Morisset, Sébastien Ciccocioppo, Ed McMullen, and Daniel Krewski. Dental amalgam and multiple sclerosis: a case-control study in Montreal, Canada. International journal of epidemiology 27, no. 4 (1998): 667-671.

Camisa C, Taylor JS, Bernat JR, Helm TN. Contact hypersensitivity to mercury in amalgam restorations may mimic oral lichen planus. Cutis. 1999; 63(3): 189-192.

Casetta, Ilaria, Matteo Invernizzi, and Enrico Granieri. Multiple sclerosis and dental amalgam: case-control study in Ferrara, Italy. Neuroepidemiology 20, no. 2 (2001): 134-137.

Clarkson TW, Magos L, Myers GJ. The toxicology of mercury—current exposures and clinical manifestations. New England Journal of Medicine. 2003; 349(18): 1731-1737.

Echeverria D, Aposhian HV, Woods JS, Heyer NJ, Aposhian MM, Bittner AC, Mahurin RK, Cianciola M. Neurobehavioral effects from exposure to dental amalgam Hgo: new distinctions between recent exposure and Hg body burden. The FASEB Journal. 1998; 12(11): 971-980.

Fulgenzi, Alessandro, Sante Guido Zanella, Mario Mauro Mariani, Daniele Vietti, and Maria Elena Ferrero. A case of multiple sclerosis improvement following removal of heavy metal intoxication. Biometals 25, no. 3 (2012): 569-576.

Huggins HA, Levy TE. Cerebrospinal fluid protein changes in multiple sclerosis after dental amalgam removal. Alternative Medicine Review. 1998 Aug;3:295-300.

Kern, Janet K., David A. Geier, Geir Bjørklund, Paul G. King, Kristin G. Homme, Boyd E. Haley, Lisa K. Sykes, and Mark R. Geier. Evidence supporting a link between dental amalgams and chronic illness, fatigue, depression, anxiety, and suicide. Neuroendocrinology Letters 35, no. 7 (2014): 535-552.

Magos L, Clarkson TW. Overview of the clinical toxicity of mercury. Annals of Clinical Biochemistry. 2006; 43(4): 257-268. 

McGrother CW, Dugmore C, Phillips MJ, Raymond NT, Garrick P, Baird WO. Multiple sclerosis, dental caries and fillings: a case-control study. British Dental Journal. 1999 Sep 11;187(5):261-4.

Mutter, J., et al. Amalgam studies: disregarding basic principles of mercury toxicity. International journal of hygiene and environmental health 207.4 (2004): 391-397.


Napier MD, Poole C, Satten GA, Ashley-Koch A, Marrie RA, Williamson DM. Heavy metals, organic solvents, and multiple sclerosis: An exploratory look at gene-environment interactions. Archives of Environmental & Occupational Health. 2016 Jan 2;71(1):26-34.

Odell, James. Biological Dentistry - Dental Mercury Amalgams.


Pamphlett R. Uptake of environmental toxicants by the locus ceruleus: a potential trigger for neurodegenerative, demyelinating and psychiatric disorders. Medical Hypotheses. 2014 Jan 31;82(1):97-104.

Pamphlett R, Jew SK. Age-Related Uptake of Heavy Metals in Human Spinal Interneurons. PloS One. 2016 Sep 9;11(9):e0162260.

Prochazkova J, Sterzl I, Kucerova H, Bartova J, Stejskal VD. The beneficial effect of amalgam replacement on health in patients with autoimmunity. Neuroendocrinology Letters. 2004 Jun 1;25(3):211-8.


Redhe O, Pleva J. Recovery from amyotrophic lateral sclerosis and from allergy after removal of dental amalgam fillings. International Journal of Risk and Safety in Medicine. 1993 Dec;4(3):229-36.

Rothwell, Janet A., and Paul J. Boyd. Amalgam dental fillings and hearing loss. International Journal of Audiology 47, no. 12 (2008): 770-776.

Siblerud RL, Kienholz E. Evidence that mercury from silver dental fillings may be an etilological factor in multiple sclerosis. Science of the Total Environment. 1994 Mar 15;142(3):191-205.

Stejskal, Jenny, and V. D. Stejskal. The role of metals in autoimmunity and the link to neuroendocrinology. Neuroendocrinology Letters 20, no. 6 (1999): 351-366.

Stejskal, Vera DM, Antero Danersund, Anders Lindvall, Romuald Hudecek, Veronica Nordman, Amer Yaqob, Wolfgang Mayer, Wilfried Bieger, and Ulf Lindh. Metal-specific lymphocytes: biomarkers of sensitivity in man. Neuroendocrinology Letters 20, no. 5 (1999): 289-298.

Tsai CP, Lee CT. Multiple sclerosis incidence associated with the soil lead and arsenic concentrations in Taiwan. PloS One. 2013 Jun 17;8(6):e65911.

United Nations Environment Programme. Minamata Convention on Mercury: Text and Annexes. 2013: 48. Available from UNEP’s Minamata Convention on Mercury website.

World Health Organization. Mercury in Health Care: Policy Paper. Geneva, Switzerland; August 2005.  

Zanella SG, di Sarsina PR. Personalization of multiple sclerosis treatments: using the chelation therapy approach. Explore: The Journal of Science and Healing. 2013 Aug 31;9(4):244-8.

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