A total of 46% of the borough’s five-year-olds have cavities, a higher percentage than those living in any other English local authority.
Data from the National Dental Epidemiology Program for 2021 to 2022 revealed that 29.3%, almost a third, of five-year-old English children have cavities.
Three other North London local authorities underperformed the national average: Harrow (35.8%), Camden (31.8%) and Barnet (30.2%).
The five-year-olds from Hackney had the best teeth in North London: 22.4% had cavities.
The percentage from other North London boroughs were: Islington (24.7%), Haringey (27.5%), Enfield (28.8%).
Overall, the national survey showed that children living in the most deprived areas of England were almost three times more likely to have tooth decay (35.1%) than those living in the least deprived areas (13.5%).
The program report says that tooth decay affecting one or more incisor (front) teeth is generally related to prolonged use of sugar-sweetened beverages in bottles, especially when given overnight or for long periods during the day.
A full 2% of children in England have advanced caries, while one in five (21.2%) children had some dental plaque.
The report says: “The cause of dental caries is well known and is related to frequent exposure of the teeth to fermentable carbohydrates, most commonly through eating and drinking sugary snacks and beverages.”
A total of 62,649 children were included in the analysis, representing 9.1% of the population of England at five years.
The report said that while inequalities in people with dental caries fell from 2008 to 2015, there have been no further declines since then.
British Dental Association Chairman Eddie Crouch said: “England’s oral health gap is widening, but ministers remain asleep at the wheel.
“Time and time again we hear the right noises, but we see literally no action to break the link between decay and deprivation.”
David Fothergill, chairman of the Local Government Association’s community wellness board, said: “Generation in oral health is expected to increase due to the magnitude of delays in primary care, which limit the ability to detect problems early. .
“The government should recommit to vital measures to combat childhood obesity and diet-related ill-health, such as the sugar tax that has helped reduce the consumption of high-sugar beverages.”