The Prime Minister says vigilance is needed after a report found 40 per cent of Kiwi five-year-olds that visited the dentist last year had tooth decay.
The figure rose in lower socio-economic regions such as Northland, where 56 per cent had some sort of tooth decay.
Ms Ardern said it was "not just about picking up the pieces". Instead, she explained, preventative care and education is imperative.
"We need to be constantly vigilant. That's one part of our dental system where access to dental care is free and accessible."
She said it was critical dental health education was available for children.
"There is a range of issues at play," she added. "The diet of an individual plays out in their oral health as well."