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Is Your Dentist “Mercury Safe?”
Many dentists have taken to using the phrase “mercury free” to describe that their practice does not use mercury amalgam fillings. This is a welcome trend, though the most recent U.S. survey showed that half of all dentists still use this “silver” dental filling material. Read how to distinguish between “mercury free” and “mercury safe.”
First, some background information. All “silver” (amalgam) fillings
contain approximately 50% mercury. This is one of the most toxic
substances on earth, and even a very small amount of mercury can be
harmful to the body. It is a fact that dental amalgam is an inherently
unstable compound, and all amalgam fillings “leak” some mercury. This
is usually in the form of mercury vapour, which is inhaled or swallowed
or absorbed into the soft mouth tissues. Mercury is the only metal that
is a liquid at room temperature. It is also volatile, emitting
colorless, odorless and tasteless mercury vapour. Any increase in
temperature significantly increases mercury vapour release. The same is
true for an amalgam filling. It is easy to demonstrate that mercury
vapour escapes from the surface of an amalgam filling, and that this
escape is dramatically increased by raising the temperature. Think: hot
coffee, friction from chewing food, or friction from getting your teeth
polished at a dental office. For a dramatic and graphic demonstration
of this mercury release from an amalgam filling, see the “Smoking
Teeth” video on the web page www.iaomt.org , the official website of
the International Academy of Oral Medicine and Toxicology (IAOMT). This
has led to a decades-old controversy over whether this filling material
should still be used in dentistry. This article won’t address that
issue, but rather the potential hazards of unsafely removing old
amalgam fillings.
Let’s try and make this a little more real with some
numbers. How much mercury exposure is safe? It would be fair to say
that no level of exposure can be guaranteed to be safe. Some agencies
have looked at what exposure levels have correlated with known mercury
toxicity problems. This includes the Occupational Safety and Health
Administration (OSHA), the World Health Organization (WHO) and the
National Institute for Occupational Safety and Health (NIOSH). They
have set exposure limits to workers with potential exposure to various
toxins in the work place. For mercury, it has been determined by WHO
and NIOSH that employers must not expose workers to a mercury
concentration in the air in excess of 50 micrograms per cubic meter of
air (50µg/m3), averaged over an 8 hour work day. Other agencies have
set this limit at 25µg/m3, and as low as 10µg/m3 for women of
childbearing age. There is also a “ceiling limit”, which means a level
of exposure that should never be exceeded even for an instant. The
ceiling limit OSHA has set is 100µg/m3.
So, what happens in a
dental office? If amalgam fillings are polished by the dentist or
dental hygienist, levels can be measured over 200µg/m3. Grinding into
an amalgam filling to remove it, without specific protective protocols,
can release mercury levels over 1,000µg/m3! These levels are generated
right at the breathing zone of the patient, the dentist, and the dental
assistant! By the way, simple toothbrushing can release mercury vapour
at a level over 200µg/m3. Please don’t take this to mean you should
stop brushing your teeth!
That means a potentially hazardous exposure to all three
(patient, dentist and assistant), every time an old amalgam filling is
removed for any reason. This is an occupational exposure that is often
overlooked, even by many dentists who consider themselves “mercury
free.” From the standpoint of OSHA regulations, a huge number of dental
offices would be in violation with respect to employee exposure. OSHA
has no jurisdiction over the patient or the dentist, but both are being
unnecessarily exposed also. Does this mean amalgam fillings should
never be replaced? Absolutely not. It means amalgam fillings should
never be removed and replaced unsafely.
There are a number of protective protocols that have been
developed by the IAOMT and others, designed to protect from this
unnecessary mercury exposure. A dentist who incorporates these
effective protocols is properly protecting his or her patients. Also
protected are the dentist and the dental staff. And, if the dentist has
taken proper measures to protect the discharged office wastewater from
mercury, the environment is also being protected. Such a dentist can be
considered “mercury safe.” The aforementioned IAOMT website also has a
short video with a brief outline of some of the mercury safe protocols.
Any dentist should adopt these procedures as a minimum of appropriate
protection. There is a more detailed and extensive training available
for dentists on being mercury safe from New Directions Dentistry
(www.newdirectionsdentistry.com), now available as a DVD training
course for dentists.
So, it can be said that “mercury free” is really a misnomer.
All dentists who ever replace an amalgam filling are dealing with
mercury in the office. How they deal with that step has a significant
impact on the potential for unnecessary, harmful exposure to toxic
mercury. A dentist who no longer places amalgam fillings and has
learned and is committed to effective protective protocols while
replacing old amalgam fillings is mercury safe.
How do you know if your dentist is mercury safe? You could ask a
few simple questions. Has the dentist taken extra, specific training in
mercury safe protocols from the IAOMT or New Directions Dentistry? Is
the patient given an oxygen nosepiece so that their breathing air is
separate and clean? Does the dentist use a rubber dam or other
protective barrier when removing amalgam fillings? There is a lot more
to it, of course, which is why training courses are offered, but if a
dentist answers “yes” to at least the above questions, they are more
likely to be committed to being mercury safe.
Is your dentist mercury safe?
Dr Ilona Visser
President, SA Chapter IAOMT
www.ctss.co.za
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