The state of Irish children’s teeth in 1985 compared “very unfavourably” with that of their counterparts in other developed countries, a government memorandum released under the 30-year rule shows.

A survey carried out to measure the effectiveness of fluoridation of water supplies found five-year-old children had, on average, two untreated decayed teeth.

“One finding of the survey which gives cause for concern is the high level of untreated dental decay which was measured by the fieldworkers,” the memorandum dated March 6th, 1985, said.

“The preliminary report of the survey concludes that the levels of untreated dental decay in Irish schoolchildren compare very unfavourably with levels in other developed countries.”

Meanwhile, 15-year-olds had an average of 1.1 untreated decayed teeth.

The survey found fluoridation of public water supplies had contributed significantly to the prevention of dental disease. The level of decay was compared with results of pre-fluoridation studies carried out in the early 1960s.

“They concluded that there has been a marked decline in the prevalence of dental decay among children in the past 20 years and that this decline has been greatest in fluoridated communities and in younger children.”

The survey was conducted by University College Cork on behalf of the then minister for health, Barry Desmond of Labour. A random sample of 9,500 children was examined by a team of field workers.

The World Health Organisation collaborated in the planning of the survey.