Mercury Amalgam Replacement

Mercury Amalgam Filling Removal

Scientific studies have not verified that dental amalgam is causing illness in the general population but there are some areas of concern in regards to mercury amalgam.
It has been known for some time that amalgam fillings release minute amounts of mercury vapour, especially with chewing, and that this mercury can be absorbed, reach body organs, and cross the placenta. This is also true of mercury absorbed from natural sources, such as food.

Also, Health Canada suggests that alternatives should be considered for patients with impaired kidney function. Although dental amalgam itself is not linked to such conditions, there is evidence that total body burden of mercury is of particular concern with these patients. Amalgam may similarly be contraindicated for workers with known occupational exposure to heavy metals or for individuals with greater than average exposure to mercury because of a diet primarily of seafood.

It should be noted that Health Canada has taken the position that “new amalgam fillings should not be placed in contact with existing metal devices in the mouth, such as braces.” Health Canada’s concern is related to galvanic effect, which occurs when two different metals are in close proximity and create the potential for electric current to be generated.

Dentists are aware of the possibility of abutting metals creating a galvanic effect. It is also recognized that galvanic effect, through corrosion of metallic dental materials, may increase the release of mercury and other elements or compounds. Some recent evidence suggests that galvanic effect may also slightly increase the release of mercury vapour from amalgam.

There is a report on mercury exposure and risks from dental amalgam which was released by Health Canada on November 27, 1995. It suggested that the number of amalgam restorations should be limited to reduce the total daily average exposure of an individual to mercury from all sources (including food, water, air and dental amalgam).

Take a common sense approach to your decisions about dental amalgam. Discuss your situation with your dentist and determine if there are special reasons to be cautious about amalgam presence in your case. Your dentist wants you to be aware of the conclusions reached in the range of scientific studies on dental amalgam.

If you have strong personal concerns, ask about alternative restorative materials (such as injectable ceramic fillings, ceramic inlays or onlays, or ceramic crowns) as your fillings need to be replaced.

Our practice uses generally accepted safe mercury amalgam removal procedures, some examples are:

1. The teeth requiring mercury amalgam removal need to be adequately isolated via a rubber dam so that the chance of absorbing and ingesting mercury vapour and particles is minimized.
2. All removals must be done under cold water spray with copious amounts of water to provide adequate cooling to reduce mercury vapour formation. Once the removal has begun, the mercury vapor will be continuously released from the tooth.
3. Therefore, A high volume evacuator tip should be kept near the tooth (1/2 inch) at all times to evacuate this vapor from the area of the patient.
4. All patients having amalgam removed are provided with an alternative clean air source and instructed to not breathe through their mouth during treatment. Clean oxygen is delivered during the procedure through a nasal cannula.
5. Adequate air filtration should be in place within the operatory area which requires a high-volume air filtration system. Therefore, a mass-air-evacuator unit is utilized to remove mercury vapour and amalgam particles generated during the procedure.
6. Particles of mercury alloy should be washed and vacuumed away as soon as they are generated. The filling should be sectioned and removed in large pieces to reduce exposure.
7. We minimize your possible exposure to toxic mercury vapours by utilizing an air filtration unit, isolation practices, source of fresh air and other dental techniques.

The information on this page are excerpts from the Canadian Dental Association FAQs on Dental Amalgam. For the complete version see the following link:

http://www.cda-adc.ca/en/oral_health/faqs/dental_amalgam_faqs.asp