Many children starting primary school in Peterborough have suffered from tooth decay, new figures from Public Health England show.
And dozens of children in the area have had teeth extracted - often requiring a trip to hospital and an operation under general anaesthetic.
With rates of tooth decay varying wildly for children in different parts of the country, dental experts have called the situation a "tragedy".
The results were based on a survey of 222 five-year-olds in Peterborough in the 2016-17 academic year, and 96,000 nationally. The survey found tooth decay in 32.4% of children - suggesting that around 970 five-year-olds in the area may be suffering with dental problems.
The rate was significantly higher than that across the rest of the East of England, with 18% of five-year-olds in the region experiencing tooth decay - either present at the time of the investigation, or evident because of missing or filled teeth.
Those children in Peterborough who were affected by tooth decay often had widespread issues, with multiple teeth affected.
The percentage of children in the sample who have needed a tooth out - 2.4% - suggests that around 70 children in Peterborough had required an extraction, aged five or younger. As high-street dentists are unable to administer a general anaesthetic, this normally requires a hospital visit.
Nationally, over 160,000 five-year-olds had tooth decay, and more than 17,000 children had teeth extracted - costing the NHS in England over £36 million a year.
The highest rate of tooth decay was in Pendle, Lancashire, where nearly half of children had evidence of decay. In Horsham, West Sussex, just 4.4% of five-year-olds had tooth decay.
The chairman of the British Dental Association, Mick Armstrong, said: "It's a tragedy that a child's oral health is still determined by their postcode and their parents' incomes.
"Sadly, while cavities are almost wholly preventable, official indifference means this inequality gap shows little sign of narrowing.
"To date England has seen little more than token efforts from ministers, and not put in a penny of new money. In the face of austerity, some farsighted councils have made big strides, but their successes are not being bottled or shared.
"The NHS will keep spending millions extracting baby teeth in overstretched hospitals until policymakers step up and grasp the nettle. When programmes and policies designed in Britain have become the envy of the world, its perverse that children in England are not benefiting from them."
Decay was found in the front teeth of 8.4% of five-year-olds, suggesting an over-reliance on the use of a feeding bottle.
Nationally, oral health among five-year-olds has been improving since the report was first issued in 2008, when 31% of children had experienced tooth decay - a figure which has dropped to 23%.