Removal and Replacement of Amalgam Fillings
Dental tooth fillings are a restorative treatment, used to improve the appearance and functionality of teeth affected by damage or decay. Amalgam fillings, made of a combination of metals, have been used for many years because they are strong, durable and relatively inexpensive. However, approximately half of an amalgam filling is composed of mercury, a metal alloy used for strengthening. When the filling begins to deteriorate over time, this mercury can leak, either as vapor or particulates, putting the patient at increased risk of mercury exposure. When the fillings eventually require replacement, as most do over time, their removal can also expose patients to mercury.
Many dental organizations recommend against replacement of amalgam fillings that are in good condition since removing them may expose the patient to an increased amount of mercury vapor. Mercury-free dentists, however, believe that the removal and replacement of amalgam fillings can be performed safely and has many health benefits.
How Mercury Enters the Body
Exposure to the dangers of mercury occurs in a number of ways. The fillings themselves give off a certain amount of vapor and small particles, which may increase with excessive gum chewing, teeth grinding or drinking of carbonated beverages. Both the vapor and the particulates may be inhaled.
Some studies have demonstrated that mercury levels in the body can increase as amalgams weaken, as well as during the replacement process when a rotating cutting tool known as a dental bur is used to chip away at the filling. Research indicates that, in addition to blood levels of mercury increasing during such procedures, urine levels of mercury can increase by as much as 50 percent and remain elevated for a month after exposure.
Dangers of Mercury
Mercury is a neurotoxin and when used as part of the amalgam in dental fillings is implanted close to the brain. While there is still some controversy surrounding the seriousness of the danger of mercury poisoning to the dental patient, it is generally agreed that vulnerable individuals, like those listed below, should not be exposed to amalgam fillings:
- Pregnant women
- Nursing mothers
- Individuals with sensitivities to mercury
- Patients with kidney disease
- Dental workers
Not only can mercury be dangerous to the individual, but is known to adversely affect the environment. Through seepage into the soil and water through dental waste, burial, or cremation, mercury can cause illness and impairment in wildlife as well as in humans.
The U.S. Food and Drug Administration, the FDA, the Council of Europe, and the World Health Organization, have all ruled that, although amalgams are more dangerous for vulnerable populations, they present a risk to the general population as well.
Strategies for Safe Removal of Amalgams
Mercury-free dentists do not use dental filling materials that contain any amount of mercury. In addition, they are specialists in the safest methods of removing amalgam fillings. The following precautions are typically taken to protect patients during amalgam filling removal:
Circulation of fresh air in the treatment room
Patient draping to prevent skin contact
Use of a saliva ejector and water spray
Cutting away the filling in large pieces
Patient rinsing with activated charcoal
These procedures are designed to prevent patient contact with the mercury in the fillings either through inhalation or skin contact. Having the patient rinse with activated charcoal or a similar substance ensures that any lingering traces of mercury are removed.
Restoration of Fillings
Once amalgam fillings have been removed, new restorative procedures are used to replace them with a material that contains no mercury. A composite material or porcelain, similar in color to the tooth, is normally used for this purpose.
- Medline Plus
- National Institutes of Health
- National Institute of Dental and Craniofacial Research
- Centers for Disease Control and Prevention
- Eunice Kennedy Shriver National Institute of Child Health and Human Development
- U.S. Department of Health & Human Services
- U.S. National Library of Medicine