As many as one in four people paying for private dental treatment is forced to do so because they cannot find an NHS practitioner, according to a survey that highlights the growing shortage of affordable dentistry.
The Consumers' Association, which did the report, believes that thousands of patients are avoiding a trip to a dentist for early treatment because they cannot afford it.
The watchdog has criticised the lack of transparency over the pricing systems, amid public confusion over what treatment is carried out by the NHS and what is performed privately.
The Government asserts that 90 per cent of the public has access to an NHS dentist via its telephone helpline, NHS Direct. Officials working for Health Minister David Lammy claim that the number of NHS dentists and the amount of treatment carried out on the health service increased last year.
But figures show that dentists' private-sector earnings are now greater than those from their NHS fees. The Observer last week ran an article on the widespread confusion over dental fees, showing that many patients are unhappy at the way they are charged for treatment when they consider themselves to be NHS patients.
A large number of readers have reported difficulties finding an NHS dentist. One is Andy Maw, a law clerk in Portsmouth, Hampshire. He had toothache for a few months before deciding to visit his dentist. Once there, he checked to make sure he was still an NHS patient. After his local anaesthetic he was told his filling cost £60.
He said: 'Despite remonstrating over the fact that I was supposed to be treated on the NHS, he said it was the kind of filling that would have to be done privately. I agreed, reluctantly, and told him I'd make out a cheque. But he wouldn't accept a cheque, so I had to walk off to a cashpoint, with my mouth becoming numb due to the effects of the anaesthetic. I had to hand over the money before he'd do the filling.'
The experience, said Maw, left him with a profound distrust of dentists.
That case is unusual, but bitterness over the charging system is not. A survey last week by the Consumers' Association showed that 48 per cent of private patients said their dentists had switched from NHS to private work. One in four said they had to pay private fees as there was no local NHS dentist available; one in four said they had not been to the dentist in the past year because of the cost. The survey covered 1,000 Scottish adults.
The British Dental Association says it has been pushing the Government for more than a year to clarify matters. Chief executive Ian Wylie said: 'We say to all our members, be clear and transparent about your charges if you provide private care. We won't defend dentists who are not clear with patients.'
Wylie says part of the problem is the complexity of NHS fees, with 300 items listed, each with a different price. Patients not exempt from NHS dental charges pay 80 per cent of the fees.
'It's absolutely bewildering,' he said. 'We need a simplified fee scale, which we could model on medicine prescription charges so that a particular procedure falls within a certain price band.'
Health department officials have told The Observer that there are more NHS dentists now than five years ago. But another set of figures tell a different story. The number of adults registered with an NHS practitioner fell from 51 per cent of the population to 44 per cent last year.
The Office of Fair Trading, soon to report on price transparency, is expected to advise that dentists inform patients early on about likely costs - and make clear whether or not treatment is on the NHS.