Underfunded programme to protect teeth leaves supplies untreated
Lack of investment has left large amounts of the public water supply untreated with fluoride, despite a recommendation more than a decade ago that it should be extended to cover the entire country.
The fluoridation of water has been credited with improving dental health and reducing decay.
However, the 2019 delivery plan of the Environmental Health Service section of the HSE said although there is a statutory requirement to extend it to all public water supplies since 2007 this has not happened.
Irish Water recently estimated extending it nationwide would incur capital costs of €20m with additional operating costs of €14.7m a year.
The HSE report said current funding levels are inadequate to maintain existing fluoridation arrangements.
"Any expansion in the fluoridation of water supplies would require additional funding," it said.
"There is an urgent need for the development of a strategy funding model for drinking water fluoridation."
In response, Irish Water said it is the "HSE that decides on what water supplies are fluoridated and provides the budget for this".
"Irish Water acts as agent of the HSE, as the local authorities did previously, in fluoridating water supplies in compliance with the limits specified in the Fluoridation of Water Supplies Regulations 2007, made by the minister for health," it said.
Studies of children's oral health consistently showed those living in areas with fluoridated water had 18pc less tooth decay than those living in non-fluoridated areas.
Dental experts say fluoride at an optimal level in the water supply provides the ideal, constant "repair kit" for teeth.
It makes them more resistant to tooth decay in people of all ages, including the young and the elderly.