floride

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.



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.