The Impact of Changing Fluoride Concentrations in the Water Supplies in the Maltese Islands on Caries Prevalence in 12-Year-Old Maltese Schoolchildren

This paper outlines the changes in the water supply system in the Maltese Islands and in fluoride concentration and the impact that this has had on the prevalence of dental caries in 12-year-old schoolchildren. It describes how over the past decades, the Maltese Islands (which comprise two main islands, Malta and Gozo) have seen changes in the water supply system, from one purely dependent on underground water which was naturally fluoridated, to one heavily dependent on desalinated seawater produced by reverse osmosis plants. This has led to the decline in the levels of fluoride in the water supply that was present naturally. Before the introduction of reverse osmosis water into the water supplies, fluoride levels in Malta averaged 0.6 ppm. In 2005, the level of fluoride in the Maltese Islands was 0.4 with a concentration of 0.15 ppm in Malta, with two-thirds of the island having undetectable amounts, and 0.65 ppm in Gozo. This may have had an impact on oral health. Since 1968, the prevalence of dental caries in 12-year-old Maltese children has seen a dramatic fall, in line with other industrialised nations, However, one study has suggested that the fall has not been smooth and between 1986 and 1995 caries prevalence in Maltese 12-year-olds appeared to rise in parallel with the changes in the fluoride content of the water supply. Nevertheless, since 1995, the decline in caries prevalence has again continued in both Malta and Gozo. It is possible that fluoride has become available through other sources, one of which may be dentifrices, the import of which increased by more than twenty-fold between 1980 and 2003.