THIS ARTICLE BY RACHEL FLINT WAS PUBLISHED ON THE BBC WEBSITE 19/9/2019.
Some parents are putting fizzy drinks and sugary milkshakes in babies' bottles, leading to rotting teeth, a dentist has warned.
Last year 21,825 tooth extractions were performed on children, 8% lower than 2014.
The Welsh Government said an education scheme had saved thousands from having their teeth pulled out.
Parents said they were trying their best, but dentists said more needed to be done to help them.
"I've seen a two-year-old have to have nearly all of his teeth taken out - it's quite distressing," said Lauren Harrhy, a dentist in Pontypool, Torfaen.
In 2009 the Designed to Smile scheme was introduced in nurseries and schools in some of the most deprived communities, after figures showed half of under-fives had tooth decay in Wales.
The Welsh Government said the scheme - which includes putting fluoride varnish on children's teeth - has helped reduce that number to a third.
But the British Dental Association (BDA) said while the programme had made "fantastic progress", more needed to be done and it was concerned the scheme was being scaled back.
Ms Harrhy said it was hard to get children to clean their teeth and parents needed to stop putting sugary drinks in babies' bottles and sugar on fruit like strawberries.
"It still happens, not as much Coke, but we do see it - but lots of people say 'I thought I'd put a bit of milkshake in because they like it', but milkshake is as sugary as Coke," she said.
Other official statistics back up the trend that rates of tooth decay are falling.
Last year 170 general anaesthetic dental procedures were performed on children aged two and under - 41% fewer than in 2014-15.
Meanwhile there has been an 8% increase in the number of examinations, suggesting more parents are taking their children to the dentist.
But the BDA is concerned some do not see a dentist at all. In April, their research found only 27% of 355 practices it surveyed were taking on new NHS child patients.
Kirsty Lee lives on the Gurnos estate in Merthyr Tydfil. Her six-year-old daughter has autism, and getting her to brush her teeth is challenging.
"Some days she will brush her teeth for me, but only if it is in the bath; other days it is just not possible," said Kirsty, who said her daughter could end up headbutting and biting her.
Kirsty said before her daughter's front baby teeth fell out they were badly decayed, but that the rest of her teeth were fine.
"We are trying our best, she goes to the dentist quite regularly, they are pretty impressed with her teeth considering," she said.
Ms Harrhy said she hoped the generation of children involved in the scheme would pass on good habits when they had children.
But she worries some are being left with a "lifelong phobia of dentists" after having general aesthetic to have most of their teeth removed.
"They are often really nervous about coming back to see a dentist in the future, the last time they came they had all their teeth taken out and they woke up sore and scared," she said.
Health Minister Vaughan Gething said the Designed to Smile scheme had made a difference and refocusing it would help new parents form good habits with their children from a young age.
But he recognised more needed to be done to support families to make more informed choices when it came to what their children eat.
"I do not believe parents set out, when they have children to leave that sort of environment where a child has to have all of their teeth removed," he said.
"It is about helping and supporting parents to make the best choices with and for their children."