Mercury Fillings - A lot of hype about nothing?

There seems to be no end to the number of speculations surrounding why people suffer from disease and ways in which to improve health status by way of alternative interventions and procedures. Due to the warranted concern surrounding overconsumption and/or exposure to mercury, some have suggested that the use of amalgam fillings in dentistry may be the cause of multiple maladies such as cognitive decline and chronic degenerative conditions. Though there is little dispute concerning the potential harm procured by the over ingestion or exposure to mercury, the causative nature of this substance in regard to significant disease markers requires further investigation to determine its legitimacy.

According to a statement made by the Food and Drug Administration (FDA), the elemental mercury contained within dental amalgam releases low levels of mercury vapor, leading to the potential for inhalation or absorption by the lungs.¹ Further, the FDA states that exposure to high levels of mercury are associated with adverse brain and kidney effects.¹ Conversely, the FDI World Dental Federation and the World Health Organization (WHO) concluded that though rare cases of local side effects of allergic reactions exist, no controlled studies have demonstrated systemic adverse effects stemming from the use of amalgam fillings in dentistry.² In addition, these organizations have stated that the mercury release resulting from the placement or removal of such fillings has also  been unproven in regard to causing adverse side effects.²  

There is a growing trend leading to the idea that not only does the exposure to mercury fillings lend itself to causing general health complaints but that the removal of amalgam fillings may also contribute to the improvement of degenerative disorders such as multiple sclerosis, Alzheimer’s disease, Parkinson’s or autoimmune disease. Clearly, drawing such conclusions must be based upon credible evidence prior to the determination of validity. Both a look at the use of amalgam fillings in relation to the onset of disease as well as the improvement of disease following amalgam removal may shed light on the so-claimed relationship. Therefore, with controversy rising regarding this topic, there is reason to investigate this body of information before drawing definitive conclusions. Looking at a couple of articles may shed further light on this issue.

A longitudinal analysis of the connection between dental amalgam removal, urine mercury levels and a set of 14 self-reported health symptoms was performed with 955 Canadian participants.3 With the premise that mercury vapor poses a health threat to those in constant contact with it, researchers studied the effects of amalgam filling removal on health compared to lack of filling removal.3 With the use of urine analysis, researchers concluded that those who had amalgam fillings measured double the urine mercury as those in the control group who did not have amalgam fillings, yet according to Health Canada, the urine mercury levels did not pose an adverse health risk.3 Results showed that participants in the treatment group who underwent amalgam removal experienced decreased levels of urine mercury.3 Outcomes of the study demonstrated that removal of amalgam fillings led to a reduced likelihood of self-reported symptoms as well as an improvement of existing symptoms when compared to those who retained their dental fillings.3 At the conclusion of the study, researchers deduced that amalgam fillings produced adverse effects on health and the removal of fillings produced favorable symptom outcomes among those tested.3 Of note, the study was funded by Pure North S’Energy Foundation, an organization focused on helping Canadians feel better and live longer by creating tailored programs for individuals interested in preventing chronic disease and living healthier lives.3 Though initially sounding credible, the organization appears to focus on questionable health practices as well as giving credence to several topics of little significance, therefore pulling into question their bias towards the topic of amalgam removal. Despite this fact, the information contained in the study ought not be completely disregarded, but should encourage caution at taking the information contained as solid proof of evidence.3 In addition, study results were largely dependent upon self-reports which are oftentimes inaccurate, again presenting need for caution when interpreting results.3

A risk assessment taking into account the literature obtained through 2005 was performed in regard to amalgam and the warranted nature of its use.4 Authors presented that though amalgam has been used in dentistry for 150 years, it is to blame for a significant contribution to the human mercury load due to continuously released mercury vapor emerging from the amalgam restorations.4 Further, authors stated the accumulation of mercury in the organs, particularly the brain, is a result of mercury’s ability to bind to proteins in a manner stronger than that of other heavy metals.4 In addition, mercury has been considered as a highly toxic, non-radioactive element which points to its potentially ill-warranted use in the human body.⁴Authors noted that recent publications suggest the influence of mercury toxicity on kidney damage,  neuropsychological impairments, induction of autoimmune diseases or sensitizations, increased oxidative stress, autism, skin and mucosal reactions, AD, MS and nonspecific discomfort.4 In addition, authors suggested the possible presence of hereditary, acquired or interindividual sensitivities in regard to the initiation of symptoms or disease.4 Though the assessment of the available literature points to the questionable safety profile of mercury levels in amalgam, authors of the current review appeared aware of the necessity of obtaining solid and evidential research in regard to making definitive claims of the healing nature of amalgam removal.4 More specifically, authors stated, “Due to methodological deficiencies, some amalgam studies are only partially usable in their statements. In some studies, amalgam removal in a relevant part of the patients could permanently improve or cure various and mostly chronic conditions. Due to the consideration of all available data, amalgam can neither be designated a medically, occupationally, nor ecologically safe dental filling material”.⁴

 Following scrutiny of the research provided above, it is likely safe to assume that there is some truth to the possible effect of dental amalgam on health outcomes. However, it does not appear that the preponderance of the evidence points to undeniable proof of mercury’s detriment to the mind and the body in the form of dental fillings. It is important to assess the risks and benefits associated with any procedure prior to initiation of the process. In terms of amalgam removal, discomfort of procedures, increased symptom load directly following removal, lack of symptom improvement and costs involved all contribute to the risks of the decision. Whether or not these risks outweigh the possible benefits suggested by prior research must be individually assessed. As with all procedures, no options exist without risk. In summary, determination of the most warranted decision is not accompanied by certainty but rather personal judgement.

**A more detailed review of the literature may be obtained upon request. 

References

1.      U.S. Food and Drug Administration. About dental amalgam fillings. Available at: https://www.fda.gov/medicaldevices/productsandmedicalprocedures/dentalproducts/dentalamalgam/ucm171094.htm. Accessibility verified September 17, 2018.

2.      American Dental Association. Statement on dental amalgam. Available at: https://www.ada.org/en/about-the-ada/ada-positions-policies-and-statements/statement-on-dental-amalgam. Accessibility verified September 17, 2018.

3.      Melchart, D., Vogt, S., Köhler, W., Streng, A., Weidenhammer, W., Kremers, L., et al. Treatment of health complaints attributed to amalgam. Journal of Dental Research. 2008; 87(4): 349–353.

4.      Mutter J, Naumann J, Walach H, Daschner F. Amalgam risk assessment with coverage of references up to 2005. Das Gesundheitswesen. 2005; 67(3): 204-16.