The UK-wide programme to screen school children for tooth decay should be scrapped because it does not improve dental health, government experts say.
Affluent children were more likely to have treatment after screening
A trial of 17,000 children found those from poor backgrounds benefit least from screening despite having much higher rates of dental disease.
The Department of Health says primary care trusts should consider investing the funds saved in other strategies.
Experts said adding fluoride to drinking water would have more impact.
Children aged six to nine years are currently screened at least three times for signs of tooth decay by dentists who go into schools.
Those found to need further treatment are sent home with a letter asking them to go to their dentist.
But research suggests follow-up is poor.
In a letter to primary care trusts (PCTs), the Department of Health said the National Screening Committee found no evidence to support continued screening.
Resources could be used more effectively to tackle oral health inequalities, the department said.
The Oral Health Unit at the National Primary Care Development Centre said screening by dentists in schools had been going on for decades.
Its study of children in the North West of England found only half of children with tooth decay in their permanent teeth made a follow-up appointment with a dentist and only 25% had appropriate treatment.
Children from affluent backgrounds were more likely to visit the dentist and receive treatment after being screened.
This was despite children from poorer backgrounds having the highest rate of tooth decay.
Study leader Dr Keith Milsom said middle-class parents were probably more likely to access health services.
"What we showed was that screening does not lead to any improvement and more importantly it does nothing to reduce inequalities between rich and poor," he said.
"This is a signal to PCTs that dental screening is dead in the water."
He said preventive strategies would be more successful.
"The holy grail would be the fluoridation of drinking water supplies, which is safe, effective and ethical.
"Only 10% of the population have access to fluoridated water," he said.
It is thought that discontinuing screening should free up 4-5% of primary dental care services.
But the National Screening Committee said even if access to dental services was improved there was likely to remain a marked social inequality in the incidence of tooth decay.
Janet Clarke, chairman of the British Dental Association's central committee for community and public health dentistry, said screening had not been the best way to tackle the poor dental health in children.
"This will give dentists the opportunity to spend more time providing dentistry to groups who have found it difficult to access care."
She added targeted water fluoridation would also be effective.
A spokesperson for the Department of Health said routine screening was not cost-effective but that PCTs could continue with the scheme if they wanted.
"The greatest improvements will come from giving parents and their children knowledge of how to prevent dental disease and obtain treatment," she said.