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Fluoride--the
misunderstood element
There is a lot of confusion
in the public mind about the health benefits of fluoride,
especially as it relates to its use in the public water
supply. Much of the confusion stems from misinformation
spread by anti-fluoridation political groups.
It is important to know that all
the information I have included here comes from
accredited scientific sources. I have referred to a
position paper published by the Journal of the
American Dietetic Association from which I have
lifted the following quote and some of the
information that follows. There is no disagreement
among accredited public health experts about the
public health benefits of fluoridated water. (Note:
The ads on this site are placed here by a Google bot
and help to support web hosting costs. They do
not necessarily reflect my views.)
"Although antifluoridationists have gained
much publicity in their attempt to create the illusion of
scientific controversy about fluoridation, claims of a
health hazard from water fluoridation are unfounded.
Fluoridation has probably been the most thoroughly studied
community health measure in recent history. The American
Dental Association cites extensive research demonstrating
that fluoridation does not increase the incidence or
mortality rate of any chronic condition, including cancer,
heart disease, intra-cranial lesions, nephritis, cirrhosis,
and Down syndrome. Results of recent studies failed to find
any correlation between fluoride in the water supply and
cancer in human beings."
The history of Fluoride
The best place to start in
understanding the relationship of fluoride to dental health
is to read my short piece about the
history of Coca Cola
and its impact on the dental health of Americans
starting in 1886, the year when Coke was first marketed.
(By the way, I like Coke, so don't take this as some sort of
indictment of the company. Coke is NOT evil, in spite of
what Pepsi says!) That date marked the beginning of one of
the most widespread and least understood pandemics (like an
epidemic, but worldwide) in history. Tooth decay became the
the most common human disease on earth. It is not well
recorded because it was so widespread, and few people died
from its effects, but it caused a lot of pain and
suffering. (Posterity sometimes fails to remember some of
the most widely known facts of the historical times. Not
many people know today that Queen Elizabeth I had black
teeth due to the recent innovation of table sugar imported
from the new world.)
By the early 1900's the
pandemic of tooth decay was in full swing all over America,
however, it was noted that people raised in certain areas of
the American Southwest seemed to be almost immune from
decay. These people had brown spots on their teeth, which
made them less attractive. Their teeth were occasionally
malformed, but were hard and very resistant to decay. Other
than that, they suffered no unusual health abnormalities.
In the 1930's researchers discovered that the prevalence and
severity of this type of discoloration (now known as
fluorosis) was directly associated with the amount of
fluoride in the water. Further research, culminating in
the late 1940's established that at optimal concentrations,
(0.7 to 1.2 parts per million) fluoride in the water supply
gave protection against decay without causing the spotted
teeth. Click
here to go to the end of
the page where I have included images of severe fluorosis
caused by naturally occurring fluoride in the ground water.
After further studies
establishing the safety and effectiveness of water
fluoridation in reducing the incidence of tooth decay, there
was a long battle to persuade the public that water
fluoridation was to their benefit. There had already been a
big fight over the introduction of
chlorine into the water
supply, (to eliminate the incidence of water born diseases
such as cholera and salmonella) and even that controversy
was not fully settled since many people still thought of
chlorine as a poison and a political plot to harm
Americans. Click
here for a short, but interesting anecdote.
Although some cities' water
supplies were fluoridated as early as the late 50's,
municipal fluoridation did not become a commonplace until
about the mid 60's. Thus many children born after about
1968 had the benefit of growing up with fluoride
incorporated into the structure of their teeth. It was in
the 1970's that the benefits of water fluoridation became
quite evident to dentists as the incidence of tooth decay
began a serious decline. There was even talk during this
period of the entire dental industry eventually
disappearing. (I'm old enough to remember it.)
Unfortunately (or fortunately, from the dentists' point of
view) that did not happen.
Today, about 65% of the
population in the US receives the benefit of fluoride in
their water systems. While the children raised under these
circumstances still get some decay as a result of the
overuse of
sugar, it is much less
severe now than it was in
years past. The
current range for water fluoridation of community water
systems is 0.7 to 1.2 ppm (equivalent to 0.7-1.2 mg/L).
Water that has fluoride at these levels is safe and
effective for preventing tooth decay.
There is NO indication that there is any difference in the
overall health of children raised with the benefit of
fluoride in their drinking water at recommended levels
(other than a high resistance to tooth decay) and those
raised in areas without this benefit. No matter how much
statistical confusion wrought by the frequent attacks of
anti-fluoridation zealots, this is one statistic that cannot
be denied! Please read the
surgeon general's statement
about fluoride.
Remember that dentists make
their living filling cavities due to tooth decay. The fact
is that the widespread presence of fluoride reduces the
frequency of decay and thus is responsible for the reduction
in the income of dentists worldwide. It is a testament to
the honesty of the profession that virtually all dentists
(and physicians) promote the use of fluoride, both as a
public health initiative and in proprietary dental products
such as toothpastes and mouthwashes in spite of the fact
that it negatively impacts their personal income.
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Dear "Doctor
Dumb Ass"
I received a
letter from an antifluoridationist,
and I thought I should share it with
you.
I am grateful to
him for making so many points. I
took the opportunity to answer each
point in his letter so that all my
readers can go direct to the
government sources which debunk the
rubbish the antifluoridationists
promote. The rebuttal is not for
the faint of heart. It contains
lots of links and dry info, but it
is all correct, well documented and
addresses the questions raised. It
is not as boring as you might think
because we have all heard these
arguments, but very few of us have
taken the time to actually look them
up. Click on the title in this box. |
How does
fluoride work?
Teeth are hard,
and this hardness is caused by a form of calcium
called hydroxyapatite. Hydroxyapatite is
the same substance that makes bones hard.
The bones have the added advantage of
an active blood supply, so the body has a
mechanism to remineralize any area of bone that
needs repair, while the teeth, once formed, must
last a lifetime without any active help from the
body's defenses.
Hydroxyapatite is
very susceptible to acid attack. The sugar you
eat is metabolized to a dilute acid in your
mouth by the germs in plaque. (This process is
covered in my page on
decay.)
Hydroxyapatite is also quite susceptible to
"attack" by free fluoride ions as well,
but instead of causing destruction of the
hydroxyapatite crystals, it causes their
transformation into fluoroapatite.
The fluoride ions essentially substitute
themselves for the hydroxyl groups in the
hydroxyapatite. Fluoroapatite has
most of the same characteristics as hydroxyapatite, but is quite resistant to
attack by acid. Thus, rinsing the mouth
with fluoride containing mouthwashes and
toothpastes coats the outside of the teeth with
a layer of acid-resistant fluoroapatite.
In addition, the fluoride will penetrate under
leaky fillings and partially remineralize the
decay underneath them.
Finally,
fluoride, given to children during the time the
teeth are forming under the gums, actually
incorporates itself into the permanent structure
of the teeth and imparts some protection from
decay for the life of the teeth themselves.
This is the reason that dentists encourage young
parents to give their children fluoride
supplements (in areas where there is none in the
water supply).
What benefits
does fluoride give to teeth?
-
Fluoride promotes the "healing" of cavities:
The regular use of fluoride containing
toothpastes and mouth rinses will
remineralize tooth structure which has been
attacked by acid. These areas tend to
harden up and will remain that way unless
more sugar undermines the remineralized
areas. The remineralized tooth structure
will remain discolored, but the decay will
become inactive if the patient cuts back on
sugar exposures and continues to apply the
fluoride. When decay remineralizes and
becomes hard, but remains black, we say that
it is "ebronated".
-
Fluoride
increases the resistance of the teeth to
acid demineralization: Any tooth
structure exposed to fluoride will gain a
surface molecular layer of fluoroapetite
which is resistant to acid attack. This
layer will wear away over time, but if the
fluoride is applied daily, the armor layer
is refreshed and the patient enjoys another
day of decay resistance.
-
Fluoride
interferes with the function of the
germs in plaque
which are responsible for turning the
sugar you eat into acid. This effect lasts
beyond the time of brushing (an effect we
call subsidence), and the number and
activity of the germs in the mouth remains
below what it would without the effect of
the fluoride rinse or toothpaste.
-
Fluoride
speeds up the formation of the internal
structure of the adult teeth after they have
begun to erupt. When teeth first erupt
into the mouth, the nerves inside them are
very large. The nerve lays down more tooth
structure inside its own space as we get
older. This has the overall effect of
strengthening the teeth since the teeth
contain more hard, mineralized material as
they mature.
-
Fluoride
given to children affects the shape of the
teeth themselves. The difference in
shape is not obvious to non dentists. The
depth of the grooves in the tops of the back
teeth is reduced by fluoride. This area is
where most early decay develops, and the
reduction in the depth of these grooves
reduces the ability of the acid to penetrate
through the enamel into the softer dentin
underneath.
Flurosis--The downside to fluoride
There is one problem
associated with fluoride. This involves the
appearance of the teeth if a child under the
age of six receives
too much fluoride while the teeth are
forming.
By the time fluoride had finally
become common in municipal water supplies, the
experts were surprised to find a fair number of
children whose teeth exhibited the white (and
sometimes orange) spots typical of fluorosis.
All the studies done during the pioneering
years of fluoride research suggested that this
just should not happen at the doses
recommended. The problem of widespread
fluorosis did not start showing up until about
the mid 1950's. The experts were very puzzled
until they realized that the fluorosis was
not caused by the fluoride intentionally
placed in the water supplies.
The problem was fluoride containing
toothpastes (which--surprise--became widespread
in the mid 1950's). When small children are encouraged
to brush their teeth, the parents generally put
toothpaste on the brush for them. Being
children, they do not know
that this sweet stuff is not
supposed to be swallowed. Unfortunately, the
typical toothpaste contains concentrated
fluoride meant to be used topically only.
Adults spit it out when they are finished
brushing, but to children, toothpaste tastes
like candy, and the more you put on the brush,
the better it tastes. In addition,
children under six have a difficult time
controlling the swallowing reflex and find it
difficult to avoid swallowing. This extra
high concentration of proprietary fluoride, when
actually swallowed by a child goes into
circulation and is deposited in the developing
adult teeth causing fluorosis.
Fluorosis can happen only during the time
that the enamel is forming on the teeth.
Since all the tooth enamel (except for the
wisdom teeth) forms before the age of six, only
children six and under are susceptible to
getting fluorosis. Fluorosis does not
happen to any portion of the teeth that have
already erupted.
It is recommended that children under the age
of six use toothpaste only under adult
supervision, and that only a "pea sized" dollop
of toothpaste be placed on the brush.
Cases like the one shown in the image
above are extreme and very unusual today.
The majority of modern cases appear like the
ones below, with white parallel lines on the
central and lateral incisors. If the
mottling is severe enough to cause
embarrassment, bleaching the teeth generally
reduces the prominence of the white spots by
whitening the natural tooth enamel surrounding
them. Unfortunately, bleaching the teeth
is not effective for removing the fluorosis
discoloration itself.
What about the pictures on
the
anti-fluoridation sites?
Internet sites that preach the
evils of fluoridation frequently exhibit horrid
images of dental fluorosis in order to scare
the public. The images above are quite graphic
and occur all over the web. A bit of history is
in order here. In the 1930s, the very first
cases of fluorosis were noted in the American
Southwest. No one knew what the cause of the
epidemic was until some local dentists did a lot
of research and pinned the cause on very high
concentrations of naturally occurring fluoride
in the water supply of some isolated
communities. Dentists in areas where this type
of deformity was endemic noted that these people
never got decay in their teeth, unlike their
neighbors who moved into the area form other
parts of the country and who's teeth were
normally shaped, but had lots of decay. It was
this observation that caused these dentists to
realize that whatever was causing the
deformation of the teeth was also causing the
resistance of the teeth to decay. Careful
research finally revealed that the very high
concentration of naturally occurring fluoride
in the local water supply was the cause of both
conditions. Fluorosis of this
severity rarely happens anymore since state
public health services prohibit the use of
drinking water with toxic levels of naturally
occurring fluoride. People who live in
areas with water that could produce this type of
deformity simply do not drink the local water.
The images you see above are
from that era of research. You will note that
the quality of the images is quite poor, and
this is the result of the state of the
technology of color photography at that time.
These people grew up in areas where the
concentration of Fluoride in the natural water
was several hundred parts per million.
Further research in 1940s revealed that using a
concentration of 0.7 to 1.2 parts per million in
drinking water could confer the benefits of
decay free teeth without the deformities seen
above.
Thus the images above are
typical of severe fluorosis, but cases like this
are rarely seen today because people who live in
areas with toxic concentrations of fluoride
(indeed with toxic concentrations of anything)
in the ground water generally drink municipal
sources that are controlled for their purity.
The other "evils" of fluoride
Antifluoridationists accuse fluoride of
causing all sorts of diseases including cancer,
bone fractures, thyroid and parathyroid disease,
heart disease, kidney disease, pineal gland
disease, Alzheimer's disease, Downs syndrome and
genetic diseases. Believe me, municipal
water fluoridation does not cause any of these
problems. I have debunked numerous claims
on my
"Dear Dr. Dumbass" page,
but for the full scoop on them, please read this
excellent 70 page long
fact sheet (in
pdf format) which not only debunks the
antifluoridationist claims, but gives the
correct scientific reference for each study that
is referenced.
Fluorides in dental
material
Regardless of how anyone feels
about fluoride, it is apparent that the dental
profession (not just in the US, but worldwide)
feels that Fluoride is a tremendous benefit for
their patients. This attitude is borne out by
the fact that fluoride is found not only in
mouth rinses and tablet form, but it is included
in the very materials used to fill your teeth.
Many tooth colored fillings placed in teeth
today either contain fluoride, or are placed
over a base or cement that does. This is done
intentionally. Many composite fillings and
cements are formulated in such a way as to leach
small amounts of fluoride into the surrounding
tooth structure to strengthen it against
recurrent decay. For more information on how
these materials are formulated, please click on
the dental materials button below.
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