Introduction

Dental amalgam restorative material has been used for many years dating back to the middle ages-and even before this period, as mentioned by Hyson in Amalgams: Its History and Perils (2006).1 The use of such materials is not new but techniques in the use of these materials has greatly improved overtime in both preparation and placement of all existing restoration materials. Postings on the internet and conversations on this subject have suggested that amalgam restorations, which contain mercury, may be contributing to and linked to oral and systemic problems. Patients who are concerned about the safety issue of amalgams are asking questions of their dental professionals. Additionally, environmental issues are of concern as well since amalgam material has been released into the environment for decades. Notations about general health problems have been especially pervasive over the past twenty years worldwide- not only for patients but for those in fields such as dentistry that involve occupational mercury exposure in the work environment. As patients read these postings and deal with their own health issues, the subject appears to surface more frequently in articles and over the internet. With the development of the internet capabilities and search modalities, it is much easier to find information, share thoughts with others and ask relative questions related to the individuals’ own health concerns. This is especially relevant for Facebook and LinkedIn users where comments and discussion often occur between groups of people.

This course provides current information on the use of amalgam in restorative dentistry, the removal of amalgam from teeth and work-related hazards associated with amalgam. It will also improve communication with the patient and determine the best practices when considering removal of the amalgam material for all those involved. This course is not to suggest that dental amalgam should be removed because of health implications, but rather to assist the clinician in determining whether an amalgam should be removed when requested by a patient.

Dental amalgam is a combination of metal materials such as silver, copper, tin and zinc that is then mixed with mercury. The total composition is 50% elemental mercury (Hgo) and 50% elemental silver along with traces of other metals added to manipulate the material. Upon mixing with the other metals such as silver, copper, and tin, the elemental mercury is converted into inorganic mercury in the form of intermetallic compounds (Ag3Hg3 + Sn7-8 Hg). Small amounts of Hgo are released from amalgam restorations and absorbed through the lungs as Hgo vapor.28 Dental amalgam has been a preferred material for restoring teeth due to decay because of its availability, adaptability and durability. Even with the concerns related to mercury, the economical factor and long-lasting quality are often two prime considerations for its use today. Since dental amalgam is considered a stable material and in the form of inorganic Hgo, the concerns have not been as great with many organizations or individuals. Methylmercury (CH3Hg), on the other hand, is found in fish and the wastewater, surface waters and the air. CH3Hg is readily absorbed within the tissues of the body and is cumulative over time. Mercury toxicity according to the California Dental Association, is determined by the form of mercury, route and duration of exposure and dose.22