Table of Contents
- 1 Everything you ever wanted to know about Fluoride
Everything you ever wanted to know about Fluoride
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 anti-fluoridationists 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 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 which works out to 0.7 to 1.2 mg of fluoride per liter) fluoride in the water supply gave protection against decay without causing the spotted teeth. Click here to see 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.
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!
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.
What compounds are used to fluoridate water?
Sodium fluoride (NaF) was the first compound used and is the reference standard. It is a white, odorless powder or crystal; the crystalline form is preferred if manual handling is used, as it minimizes dust. It is more expensive than the other compounds, but is easily handled and is usually used by smaller utility companies.
Fluorosilicic acid (H2SiF6) is an inexpensive liquid by-product of phosphate fertilizer manufacture. It comes in varying strengths, typically 23–25%; because it contains so much water, shipping can be expensive. It is also known as hexafluorosilicic, hexafluosilicic, hydrofluosilicic, and silicofluoric acid.
Sodium fluorosilicate (Na2SiF6) is a powder or very fine crystal that is easier to ship than fluorosilicic acid. It is also known as sodium silicofluoride
The controversy surrounding fluoridation of public water supplies
There are essentially three arguments against fluoridation of municipal water supplies..
The first argument is about the personal health effects of daily intake of low levels of fluoride in drinking water. The safety of low levels of fluoride in drinking water has been studied for over 50 years, and in spite of tremendous efforts on the part of antifluoridationsists, no scientifically verifiable evidence has come to light that fluoride in concentrations used to fluoridate municipal water supplies causes any health risk.
The second argument against government controlled fluoridation of water supplies is essentially libertarian in nature, and this argument has carried the day in some areas of the world. The libertarian argument views fluoride as a medication, and revolves around the ethical responsibilities of governments to deliver a a medication to individuals within the general public, some of whom may object to the government imposing its will on them. Regardless of the health benefits conferred on the population as a whole, this argument is legitimate and is part of the the reason that the practice of water fluoridation has been stopped in a number of countries in Europe.
The third argument against water fluoridation involves its practicality in any given area. Ireland and the United Kingdom are in fact fluoridated, while numerous other continental nations rely on fluoride supplementation of salt (similar to the way salt in the US is supplemented with iodine). Basil Switzerland ceased water fluoridation in 1963 principally because trade barriers that had prevented fluoridated salt from being sold there were dismantled, and the combination of fluoridated salt and fluoridated water would have raised the national fluoride intake above recommended levels. The difference between continental Europe and the US apparently revolves around the complexity of the various water systems found in European metropolitan areas, making salt supplementation a more practical method of distributing fluoride than water fluoridation. This is particularly true in newly liberated Eastern European countries. The advantage to salt fluoridation is that it does not rely on a centralized piped water system. Although water fluoridation is not carried out in Sweden or the Netherlands, both countries support the World Health Organizations regarding fluoridation as a preventive measure in addition to the use of fluoride toothpastes, mouth rinses and dietary fluoride supplements.
I received a letter from an anti-fluoridationist, 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 anti-fluoridationists 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.
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 “eburnated“.
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.