by Dr. Nizar Kharma
What is Fluoride?
Fluoride is a compound of fluorine, which is one of the 118 elements that make up our universe. Fluorine can combine with other elements to form fluorine-containing salts. These salts, the most popular of which is sodium fluoride, are added to water supplies, toothpaste and other dental products in order to reduce tooth decay.
Why is Fluoride so Important in Dentistry?
The useful effect of fluoride in preventing dental decay has been an established evidence-based fact in dentistry and dental education for decades. Dental studies from as early as the 1930’s show a strong association between fluoride use and caries reduction in most populations. Fluoride reduces tooth decay, mainly in the outermost enamel layer, by the formation of fluorapatite within the structure of the enamel. The fluoride ions in the fluorapatite then reduce enamel demineralization and increase its re-mineralization, which consequently prevents the early formation of decay. 
Different Types of Fluoride Therapy:
- Toothpaste: This is the most popular mode of exposure to fluoride, usually containing 0.3 percent fluoride for adults and between 0.1 and 0.2 percent fluoride for children under 7 years of age.
- Mouth-Rinses: The typical fluoride mouthwash concentration is 0.05 percent sodium fluoride. These are generally not recommended for young children due to the high risk of swallowing.
- Professionally Applied Gel/Foam/Varnish and Slow Releasing Devices:Fluoride gel or foam is usually applied using a mouth tray containing the product. The tray is held in the mouth by biting for four minutes. The varnish on the other hand is easier to use — it’s applied with a brush and sets within seconds; it also has a milder taste. Slow-releasing devices are placed on the surface of a tooth (typically the upper first molars). They have been proven effective in preventing decay, but can easily fall off. 
- Professionally Prescribed Fluoride Supplements: These include high strength fluoride toothpaste (containing 1.1 percent sodium fluoride), which is mainly prescribed for high-risk adults and teenagers. Children at higher risk of cavities are usually prescribed fluoride tablets, lozenges, liquids or droplets.
- Drinking Water Fluoridation: This involves the addition of fluoride (typically 0.5 to 1 mg/l) to public water supplies with the aim of reducing tooth decay as is being implemented in Qatar. Water fluoridation is considered the most cost effective method of fluoride therapy as confirmed by many dental studies and recommended by reputable public health organizations.
Indications for Professionally Applied/Prescribed Fluoride Supplements/Appliances:
- Patients at moderate to high risk for developing decay. This includes patients undergoing orthodontic treatment as well as those with a large number of decayed or already filled teeth.
- Patients suffering from decreased salivary flow, as saliva contains decay-fighting antibacterial compounds.
- Institutionalized patients, as maintaining satisfactory oral hygiene becomes more challenging, therefore increasing patients’ risk of tooth-decay. 
- Tooth sensitivity reduction.
- Protecting exposed root surfaces.
- White patches implying early enamel decay. This can usually be reversed by early exposure to fluoride.
The Drinking Water Fluoridation Controversy
Water fluoridation has historically received strong support. Despite that, a growing anti- fluoridation movement has become increasingly popular in the last two decades. Both enthusiasts and opponents have convincing arguments:
- Evidence supporting drinking water fluoridation:A Systematic Review on water fluoridation published in the British Medical Journal in September 2000 reviewed 214 studies on the subject. It concluded that there is a statistically significant increase in the proportion of children without caries and a reduction in the number of teeth affected by caries in fluoridated areas, compared to non-fluoridated areas.  Several other studies conducted in the USA, Europe, Australia and New Zealand have also confirmed the same cost effective benefit of water fluoridation. [1,2,3,4,5]
- Bone strength: Some studies have even shown a correlation between drinking water fluoridation and stronger, denser bones.
- Fluorosis:The harmful effects of fluoride therapy and water fluoridation are rare, with the most often recorded being mild fluorosis (teeth mottling) which is seldom aesthetically concerning, and easily managed. 
- Any other harmful effects such as fluoride poisoning are extremely rare and easily preventable. 
- Any link to bone cancer or fragility is scientifically invalid. 
- Weak evidence of fluoride benefits: The increasingly outspoken opposition voices argue that some studies showing the statistically significant or even harmful effects of fluoride are ignored by fluoride enthusiasts. For example, the Systematic Review mentioned earlier clearly states that the quality of the studies analyzed was “low to moderate”. In addition, most of the other studies used to prove the positive effects of water fluoridation lack the two most important elements of strong research: randomization and blinding. This inevitably results in bias, which largely affects the credibility of any research. Moreover, almost all the useful effects of fluoride and fluoridation are shown only in children’s permanent teeth, therefore excluding deciduous teeth as well as adults’ permanent teeth. 
- Available evidence against fluoridation: Numerous studies show no significant reduction in decay in fluoridated areas. Interestingly, a study of a previously fluoridated area in Cuba concluded that the rate of decay decreased when drinking water in the area became non-fluoridated. The study argued that tooth decay rates decreased due to better oral hygiene, diet and better use of fluoride toothpaste but that fluoridation had no significant role to play in decay reduction. Furthermore, some studies show that systemic fluoride intake (drinking water fluoridation for example) is far less effective against decay than topical fluoride in the form of toothpaste, mouthwash, gel or lozenges. Finally, an increasing number of studies demonstrate a decreasing difference in dental decay between fluoridated and non-fluoridated areas in developed countries.  This is most likely due to people in both fluoridated and non-fluoridated areas adopting better dietary and oral hygiene habits, in addition to fluoride use in the form of toothpaste and other supplements, therefore reducing any beneficiary effect from water fluoridation.
- Available evidence against fluoride: Some studies have shown that fluoride in any form or concentration is actually harmful to the teeth, brain and bones, and may even be linked to bone cancer.  The studies also argue that dental decay in the developed world started to decline in the 1930’s, mainly due to lower sugar consumption, and at least 10 years before the introduction of fluoride toothpaste and fluoride dental products. Moreover, researchers from Harvard School of Public Health and China Medical University in Shenyang combined 27 studies and found strong indications that fluoride may adversely affect cognitive development and brain development in children, and could potentially lower their IQ.
- Freedom of Choice: From a politico-ethical point of view, opponents argue that drinking fluoridated water is a personal choice and should not be imposed on people.
- Fluorosis: The Systematic Review published in the British Medical Journal found that 1 in 8 subjects exposed to drinking water fluoridation had fluorosis that they found aesthetically concerning. This is a relatively high proportion, which strengthens the argument against fluoridation. 
To Continue Fluoridation in Qatar or Not, Is that the Question in Qatar?
In order to decide which option is best for us here in Qatar, it is important to ask the following question: Are there enough balanced, unbiased and relevant studies in Qatar or the region to draw conclusions from? It is worth mentioning that highly developed countries such as Denmark, Sweden and Holland have rejected fluoridation, perhaps because of their relatively low decay rates, thanks to excellent dietary, oral hygiene and fluoride use habits. Therefore, if the answer to the above question is no, it may be logical to focus on promoting better oral health, while quality local studies are being conducted. To conclude, it is unlikely that the fluoridation debate will be resolved soon.
Have your say — what do you think about fluoride? Comment on Facebook or on our website, we want to know what you think!