Amalgam Fillings

What is an amalgam filling and when were amalgam fillings first used?

Closeup View of Dental Fillings Inside a Human Mouth Dental amalgam is a dental filling material.  It has been in dentistry for over 150 years, when the "Crawcour brothers" brought amalgam to the United States in 1833. They introduced the early amalgam formula, which consisted of silver filings mixed with mercury. They claimed that, with what we now refer to as dental amalgam, "with their amazing Royal Mineral Succedaneum, they could make a tooth as good as new—cheaply, painlessly and in just two minutes."

People would flock to the Crawcours for treatment because at that time the alternative was to spend hours in the dentist's chair having their mouth clamped uncomfortably open while the dentist hammers gold foil into their tooth.  The poor quality of the amalgam lead to the "amalgam war" from the period between 1840 to 1850 with bitter controversy between opposing groups.  From the 1860s to 1890s experiments undertaken to develop improved amalgam formulations lead to what dentists today use.

What is the composition of dental amalgam?

Dental amalgam is a mixture of metals, consisting of liquid mercury and a powdered alloy composed of mainly silver, tin and copper. It can be used in individuals of various ages, in stress bearing areas, foundation for crowns and in people considered to be at high risk of developing tooth decay. Whilst not aesthetic, it is considered one of the most best value for money filling materials due to its relatively low cost, strength, durability and ease of application. It is commonly referred as "silver fillings" because of its silver-like appearance, although the surface silver colour tends to darken as it ages.

Are Dental Amalgam fillings toxic?

Dental amalgam has been studied and reviewed extensively to established if there are links between its use and any associated health and safety affects. To date, the best available scientific evidence tells us that use of dental amalgams used as a tooth restorative material is considered to be safe and do not pose a health risk, to the exclusion of rare instances of allergic reactions. There is no evidence that mercury released from amalgams results in adverse health effects in the general population.

In 1997 the World Health Organization released the following statement titled:

"WHO Consensus Statement on Dental Amalgam." It states:

"Dental amalgam restorations are considered safe, but components of amalgam and other dental restorative materials may, in care instances, cause local side effects or allergic reactions. The small amount of mercury released from amalgam restorations, especially during placement and removal, has not been shown to cause any other adverse health effects.

Because of concerns over adverse effects of mercury, some patients with or without symptoms, may request the removal of their amalgam restorations. While there has been a number of case studies and informal reports, no controlled studies have been published demonstrating systemic adverse effects from amalgam restorations. At present, there is no scientific evidence showing that general symptoms are relieved by the removal of amalgam restorations. Therefore, after a comprehensive oral examination and appropriate dental treatment, these patients should be considered for referral to other healthcare professionals for diagnosis and treatment if symptoms persist."Press here to download PDF

In 2004, the Life Sciences Research Office (LSRO) and funded by the National Institutes of Dental and Craniofacial Research, National Institutes of Health and the Centers for Devices and Radiological Health, U.S. Food and Drug Administration (FDA) reviewed the scientific date from 1996 to December 2003 on potential adverse human health effects caused by dental amalgam and stated that:

"The current data are insufficient to support an association between mercury release from dental amalgam and the various complaints that have been attributed to this restoration material. These complaints are broad and nonspecific compared to the well-defined set of effects that have been documented for occupational and accidental elemental mercury exposures. Individuals with dental amalgam-attributed complaints had neither elevated urinary mercury nor increased prevalence of hypersensitivity to dental amalgam or mercury when compared with controls." Press here to download PDF

Whilst, there is a large body of research pertaining to this issue, with conclusions similar to that of the above,  there seems to be always some form of resistance against the overwhelming scientific data that support the position that amalgams fillings are a safe restorative option for both children and adults.  What remains is for the reader to make important distinctions between known scientific facts and hypothetical risks, speculation or conjecture.

Why is mercury used in dental amalgam?

Approximately half of a dental filling is liquid mercury and the other half is a powdered alloy of silver, tin, and copper. Mercury is used to bind the alloy particles together into a strong, durable, and solid filling. Mercury's unique properties (it is the only metal that is a liquid at room temperature and that bonds well with the powdered alloy) make it an important component of dental amalgam that contributes to its durability.

If I am concerned about the mercury in dental amalgam, should I have my fillings removed?

If your fillings are in good condition and there is no decay beneath the filling, It is not recommended that you have your amalgam fillings removed or replaced unless it is failing. Removing sound amalgam fillings may result in unnecessary loss of healthy tooth structure, and exposes you to additional mercury vapor released during the removal process.

However, if you believe you have an allergy or sensitivity to mercury or any of the other metals in dental amalgam (such as silver, tin, or copper), discuss treatment options with us at North Road Dental Centre in Bentleigh.
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