Fluoride is of interest because of its effects on dental enamel and bone. It comes from the element fluorine, the 17th most abundant element in earth’s crust. It is a gas and never occurs in free form in the nature. Fluorine exists only in combination with other elements as fluoride compound, which are constituents of minerals in the rocks and soil. As water passes over rock formations it dissolves fluoride compounds that are present, creating fluoride ions. As a result of this, small amounts of soluble fluoride ions are present in all water sources including oceans. Fluoride is present to some extent in all foods and beverages, but concentrations vary widely.

How do we get fluoride?

            Fluoride is obtained in two forms.

n  Systemic Fluoride: These are obtained through ingestion of water and foods containing fluorides. They become incorporated into forming tooth structures. Unlike the topical fluorides, systemic fluorides are ingested throughout the entire surface and provide longer lasting protection than those applied topically. Systemically ingested fluoride can also provide topical protection because, as part of ingested fluoride is present in saliva, which continually bathes the teeth, thus providing a reservoir of fluoride that can be incorporated into tooth surface to prevent decay, also becomes incorporated into dental plaque and facilities remineralisation.

n  Topical Fluoride: Topical fluorides strengthen teeth already present in the mouth. Fluoride given topically gets incorporated into the surface of teeth making them more decay resistant. Topically applied fluoride provides local protection to the tooth surface. This is available through tooth pastes, mouth rinses and professionally applied fluoride gels.

Does fluoride really offer protection against tooth decay?

            Yes, indeed fluoride offers, proven protection against tooth decay, through three specific mechanisms:

How important is remineralisation produced by fluoride?

            The remineralisation effect of fluoride is of prime importance. The fluoride ion in and at the enamel surface results in fortified enamel that can repair the early decay.
Fluoride ions essential for remineralisation are provided by fluoridation of water, as well as various fluoride containing tooth pastes.

What is “Water fluoridation”?

            Water fluoridation is adjustment of natural fluoride concentration of fluoride deficient water to the level recommended for optimal dental health, which is about (0.7 to 1.2 ppm). If fluoride level is less than 0.7ppm then it is considered as suboptimal level.

How beneficial and effective is “Water fluoridation”?

            Optimally fluoridated water gives all the benefit like that naturally available fluoride in water. Studies have shown that artificially fluoridated water and naturally fluoridated water have produced similar decay reducing effect.

Does fluoridation of water benefit adults?

            Fluoridation plays a protective role against dental decay throughout life, benefiting both children and adults. In fact, inadequate exposure to fluoride places children and adults in the high risk category of dental decay. In adults fluoride has both a systemic and topical effect and is beneficial in two ways. First is through remineralisation process in enamel. This can prevent enlargement of decay and can reverse the process. Secondly fluoride present in saliva provides a reservoir of fluoride ions that can be incorporated into the tooth surface to prevent decay. Similarly fluoride also is incorporated into exposed root surface structure, following gumline recession, making it decay resistant.

What are the sources of fluoride for children if technically water fluoridation is possible?

            For children who do not live in fluoridated communities, dietary fluoride supplements are an effective alternative to water fluoridation for prevention of tooth decay. Another method used to meet the fluoride need is through salt fluoridation. Salt fluoridation is used in over 30 countries, including Switzerland, Columbia, Jamaica, Costa Rica, Mexico, France, Spain and Germany. Study shows that for 12 years old children, the initial level of decay reduction due to salt fluoridation is between 35% and 80%.

Is water fluoridation still the effective method for preventing tooth decay?

            Yes, water fluoridation continues to be a very effective method for preventing tooth decay for children, adolescents and adults.

Is tooth decay still a serious problem?

            Yes, tooth decay or dental decay as an infectious disease continues to be a significant oral health problem. Tooth decay is by far the most common and costly oral health problems in all age groups. It is one of the principal causes of tooth loss from early childhood through middle age. A dramatic increase in tooth loss occurs among people from 35 through 44 years of age.

Does tooth decay increases with age?

            Yes. Since older adults experience more problems with gumline recession, the prevalence of tooth decay increases with age. Data from the 1988-1991 National Health and Nutrition Examination Survey (NHANES III) showed that 22.5% of all adults with natural teeth experienced root decay.

            This percentage increased markedly with age.

   n  18 to 24 years age group only 6% experienced tooth decay.
   n  35 to 44 year age group only 20.8% experienced tooth decay.
   n  55 to 64 year age group only 38.2% showed evidence of tooth decay.
   n  Over 75 years age group, nearly 56% had tooth decay.

            Further, decreased salivary flow or xerostomia in old age places the individual in high risk category. Decreases in salivary flow can increase the likelihood of dental decay, because saliva contains many elements necessary for early decay repair including fluoride.

What are other benefits of fluoridation of water?

            Water fluoridation contributes much more to over all health than simply reducing tooth decay. It prevents needless infection, pain suffering and loss of teeth, improves quality of life and saves vast sums of money in dental treatment costs. Additionally, fluoridation conserves natural tooth structure by preventing the need for filling and subsequent replacement fillings.

What happens if water fluoridation is discontinued?

            Dental decay can be expected to increase if water fluoridation in a community is discontinued for one year or more, even if topical products such as fluoride toothpaste and fluoride rinses are available.