At least 84,000 children are waiting for dental services, with half of these on lists for more than a year.
The figures have been described as "truly scandalous" and "a disgrace". They include children eligible for routine screening and follow-up treatment, as well as those who require orthodontic measures like braces.
The figures were provided to Fianna Fáil by the HSE's nine Community Healthcare Organisations (CHOs).
:: At least 84,000 children are on waiting lists for dental assessment or treatment;
:: 42,000 children have been waiting more than a year for dental services;
:: More than 22,900 children were on waiting lists in a CHO that includes Carlow, Kilkenny, south Tipperary, Waterford and Wexford;
:: In Galway alone there were 14,000 children waiting more than a year for a dental assessment;
:: Nationwide, 1,000 children were waiting more than four years for orthodontic services.
The HSE provides free orthodontic treatment for patients with the most severe and complex needs.
It provides routine preventative and treatment services to children in primary schools, typically first, second and sixth class. Fourth class children are also being seen in some parts of the country. These services are also free.
Waiting figures for routine primary school assessments may be far higher.
For example, the CHO, which covers Dublin north city and county, said there were 24,000 primary school children eligible for screening appointments in second, fourth and sixth classes. It said that due to staff shortages some of these children cannot be offered an appointment but did not say how many. Fianna Fáil's children spokesperson Anne Rabbitte said the number of children waiting for dental care, and the length of time they're on lists is "truly scandalous".
"What is clear is that tens of thousands of children and teenagers are waiting years for dental and orthodontic work," said the Galway East TD.
"The system appears to be completely haphazard with some children not even receiving an appointment in their targeted school year.
"We need to see a plan to target these excessive waiting lists."
Irish Dental Association chief executive Fintan Hourihan said the figures are a "disgrace" and probably underestimate the problem.
He claimed "waiting lists have just got longer and longer" and "children are being put through unnecessary pain and distress while the State has to pay the cost of remedial treatment".
A HSE statement said emergency relief of pain, infection and trauma is available to all children at local HSE dental clinics on a same-day or following-day basis. It said around 70,000 children present each year under such circumstances.
It said almost one million children up to and including 15 years are eligible for free dental services. The HSE said the number of dentists and consultant and specialist orthodontists employed by the HSE increased in 2018. It said the Department of Health is developing a National Oral Health Policy, which is expected to be published early this year.