One in three children in some parts of Wales will have decayed teeth removed before starting school.
Caitlin, aged five, has already had teeth removed
BBC Wales' Week in Week Out programme has learned that figures to be published next year will show no improvement in child dental health.
Every year, 10,000 Welsh youngsters have rotten teeth pulled out under general anaesthetic.
The programme says many dentists and health advisers believe the answer is adding fluoride to water supplies.
Caitlin Goodwin, aged five, from Newbridge, had to have five bad teeth taken out in hospital.
Her elder sisters have both had similar dental problems, and underwent multiple extractions in their early years.
But mother Nicola said parents face a real dilemma.
"You can't say no to all their sweets and things because they're only children at the end of the day," she said. "You have to strike a balance."
The state of children's teeth is an even bigger problem in deprived areas, the programme claims.
In the area where Caitlin Goodwin lives, 60% of children under five have had fillings or extractions.
In Merthyr Vale, 29% of children under five has had teeth out under general anaesthetic.
The latest figures - which will be published early next year - are expected to show no change, in spite of Welsh Assembly Government targets to improve children's dental health.
Education about dental hygiene is vital
"Somehow we have got to get fluoride in contact with people's teeth," said Professor Elizabeth Treasure of the Cardiff dental school. "Someone has to make that decision."
Some dentists blame bad parenting for the poor state of children's teeth, including Brecon dentist Tony Lees - an outspoken opponent of fluoridation.
"Why should we all have to drink this stuff because of the sake of a few families who, because of ignorance, don't get the right diet?" he argued.
Dr Steve Boyle, director of community dentistry in Gwent, said: "In some of the poorer areas you will see some of the same dental disease that I've seen for the past 20 years.
"There's been no improvement, as far as I can see, in comparison to the UK as a whole, who have benefited enormously from big improvements in child dental health."
A spokesman for the Welsh Assembly Government said Health Minister Jane Hutt could not give an interview to discuss the questions raised because her diary was full.
Week In Week Out is on BBC One Wales on 26 October at 2235 BST