Mercury is an essential component of dental amalgam. It is used to properly amalgamate the alloy particles to form a uniform mix. The amount of mercury in dental amalgam depends upon the type of alloy which is used. Generally amalgam fillings contain 50% mercury. The better method of reducing mercury content is to reduce the original mercury: alloy ratio. With this 50% or less mercury will be in final restoration, with obvious advantages.
REASON WHY MERCURY IN DENTAL AMALGAM IS SAFE.?
Dental amalgam contains elemental mercury combined with other metals such as silver, copper, tin and zinc which forms a safe , stable cavity filling material. It’s important to note that dental amalgam has entirely different properties than mercury by itself. Earlier it was believed that dental amalgam fillings in mothers leads to small babies and causes neurological problems etc. But new study by scientists and F.D.A. backs dental amalgam. According to them mercury fillings in mothers don’t lead to small babies. In their study they found that even women who had as many as eleven fillings during pregnancy were not more likely to give birth to a low weight child. Dental amalgam fillings are therefore safe and hence mercury in dental amalgam is safe.
CAUTION : IF MERCURY IS NOT MANAGED PROPERLY IN DENTAL OFFICE THEN IT CAN PROVE TOXIC AND HAZARDOUS TO THE PATIENT, DENTIST AND DENTAL STAFF AND CAUSE MERCURY TOXICITY.
Mercury is toxic. Free mercury should not be sprayed or exposed. Mercury is a liquid metal at ordinary temperatures and pressures. More importantly it is a reactive element. The present danger presents itself as a chronic low level exposure,also known as mercurialism or micromercurialism.
The chances of mercury poisoning most commonly occurs due to IMPROPER MANIPULATION AND HANDLING OF MERCURY IN DENTAL OFFICE. This is the most common cause of mercury toxicity. Mercury is not harmful when used in amalgam in the oral cavity. The only reason or cause of mercury toxicity is exposure to mercury in dental office due to improper handling. There are several sources of mercury in the dental office
SOURCES OF MERCURY EXPOSURE IN DENTAL OFFICE
- Some mercury vapor released from stored materials.
- Small losses from capsules during trituration.
- Spillage during manipulation for tooth restorations.
- Some vapor exposures to dentist, assistant and patient during removal, placement or finishing or polishing of amalgam.·
- Contamination of cotton rolls.
- Collection of debris via vaccum suction into plumbing system and sewer system.
- Collection of remnants in jar for recycling.·
- Mercury trapped in small cracks between floor tiles or in carpet fibers.·
- Exposure through direct skin contact with mercury·
- Malfunctioning amalgamators, leaky amalgam capsules or malfunctioning bulk mercury dispensers.
EXPOSURE TO MERCURY
DIET (non fish) 0.4
An average individual absorbs about 5.7 micrograms of total mercury per day. A dental amalgam fillings only adds 1-3 micrograms to that amount.
ADVERSE EFFECTS DUE TO MERCURY EXPOSURE
Certain adverse effects which can be due to mercury exposure are:
- It can cause Depression, fatigue, insomnia, tremor, and loss of appetite are the most common symptoms.
- Neurological and gastrointestinal problems
- Diarrhea ,eczema, muscle pain, headache.
Similar to all other materials in the world, mercury has the potential to be hazardous if not managed properly.
HEALTH CANADA states that there is no indication that this mercury is causing health problems if used in dental fillings. There is no reason to ban amalgams nor is there any reason to remove existing amalgams from patients. It’s recommendations to dentists include:
- Amalgams should not be placed if a patient has kidney function problems.
- If patients have a hypersensitivity to mercury, they should not receive amalgams.
- Non mercury materials should be used for restorations in children.
- Dentists should give their patients enough information to allow the patient to make an informed decision about restorations.
- Patients have the right to refuse the use of any dental restoration material.
DENTAL MERCURY HYGIENE RECOMMENDATIONS
- All trained personnel should be used in dental clinics.
- Dentists should work in well ventilated spaces with fresh air exchanges and outside exhaust.
- Periodically dental operatory atmosphere should be checked for mercury vapor
- Only pre-capsulated alloys should be used.
- Amalgamators with completely enclosed arm should be used.
- Avoid skin contact with mercury or freshly mixed amalgam.
- Use high volume evacuation when finishing and removing amalgam
- When feasible, recycle amalgam scrap and waste amalgam.
- Salvage and store all scrap amalgam in a tightly closed container under water, glycerin or spent X-ray fixer. The jar should be nearly filled with liquid to minimize the gas space where mercury vapor can collect.
- No more than a small jar of material should be present in the office at any time.
- Dispose off mercury contaminated items in sealed bags according to applicable regulations.
- Spent capsules and mercury contaminated cotton rolls or paper napkins should not be thrown out with regular trash.