Proper use of fluoride products in fluoridated communities

Abstract

The decision to add 1 mg fluoride per litre of water (or 1 ppm) was based on an extensive series of epidemiological surveys in communities with different concentrations of fluoride in their drinking water. These surveys had shown that in communities with fluoride at 1 ppm the prevalence of dental caries was 50‐65% lower than that in communities with only trace levels of fluoride. Only 10‐12% of children showed evidence of the mildest forms of dental fluorosis. 2 Dental fluorosis is a hypomineralisation of enamel of teeth caused by the chronic ingestion of excessive amounts of fluoride during the period when teeth are forming within the jaw. 3 Milder forms of dental fluorosis are characterised by whitish spots, striations, or diffuse opacities of teeth. Fluorosis does not affect the health of teeth or of an individual, but, in its more severe forms, may cause cosmetic concerns. Permanent teeth other than third molars are susceptible to the development of fluorosis in children aged up to 6 years. Excessive fluoride ingestion early in life tends to produce fluorosis in early forming and erupting permanent teeth, the incisors and first molars, whereas excessive ingestion in the later preschool years affects later forming and erupting permanent teeth, the canines, premolars, and second molars. In the 1950s and 1960s, several countries started to fluoridate their water. Hong Kong and Singapore fluoridated all their water supplies, and countries that provide fluoridated water to more than half their residents include Australia, Ireland, New Zealand, and the USA. Other countries with large water-fluoridation programmes include Brazil, Canada, Chile, and Malaysia. At the time fluoridation programmes began, fluoride that occurred naturally in drinking water and that which occurred naturally in some foods, primarily tea, seafood, and some grains, were essentially the only sources of ingested fluoride. Since then, several fluoride-containing products have been developed as alternatives to fluoridated water (dietary fluoride supplements) or as agents to provide fluoride topically to erupted teeth (fluoride toothpastes and mouth rinses and solutions, gels, and varnishes for professional application). About 20 years ago, investigators began to notice increased prevalences of dental fluorosis in school-aged children who were participants in epidemiological surveys or in clinical field trials in countries with established market economies. Most of the fluorosis observed was still mild, but there have been some increases as well in the intensity of fluorosis. Increases in the prevalence of fluorosis have been noted in non-fluoridated as well as fluoridated communities. 4 , 5