An increasing number of five-year-olds are presenting with tooth decay, according to the first all-Ireland study of children's dental health.
The study, which will be published today, states that the trend is a cause for concern.
One reason for the problem could be an increase in the frequency of sugar intake in snack foods and drinks, one of the study's authors, Dr Helen Whelton, said yesterday. She is director of the Oral Services Research Centre at the Cork Dental School.
The study, which looked at the teeth of 19,950 children and adolescents North and South, found that children in the South, where water is generally fluoridated, had less tooth decay than children in the North, where water supplies are not fluoridated.
"For example, for every 1,000 15-year-old lifetime residents of fluoridated communities in the Republic, there are an estimated 2,100 decayed, missing or filled teeth.
"The corresponding figure for residents of non-fluoridated communities in the Republic is 3,200 (1,100 more decayed, missing or filled teeth). For residents in Northern Ireland, which is non-fluoridated, the figure is 3,600 (1,500 more decayed, missing or filled teeth)," the report states.
This means that 47 per cent of five-year-olds in non-fluoridated communities have one or more decayed, missing or filled teeth compared to 30 per cent of five-year-olds in areas where water is fluoridated.
However, the report also found an increase in the prevalence of enamel fluorosis or white mottling of the teeth since a similar study was conducted in the Republic in 1984. Fluorosis results from an excess intake of fluoride.
"It is expected that adherence to the recommendations regarding the level of fluoride in the water and the use of fluoride toothpastes by infants and young children contained within the recent report of the Forum on Water Fluoridation in Ireland will address this trend," the report said. The forum suggested fluoridated toothpaste should not be used by children under the age of two.
Furthermore the survey found that in general the oral health of the less well off, North and South, was worse than that of the rest of the population.
Overall the level of dental decay found in both fluoridated and non-fluoridated areas declined since the 1984 report but this one warns there is "little cause for complacency" as tooth decay continues to be very common among children.