People are finding it no easier to see an NHS dentist a year after radical reforms of NHS dentistry came into effect, according to two reports.
The new contract started last April
A British Dental Association poll of 394 dentists found the majority did not think the reforms had improved access.
And Citizens Advice said 2m patients did not have access to an NHS dentist and were being forced to go private, go on waiting lists or do without.
However, the government said improvements were being made.
The reports come just days after a Which? survey of dentists found that two-thirds were turning away patients and as the BDA hosts a conference in London on the situation.
The government introduced a new deal last April giving dentists the same money for treating fewer patients in a bid to get away from the "drill and fill" culture and attract more dentists to the NHS.
Primary care trusts, which hold the purse strings for local health services, were also given responsibility for ensuring patients could get access to care.
They were given a budget of £2.3bn to achieve this, although a quarter of that was expected to come from fees from charges - most adults have to contribute to the cost of NHS treatment.
But PCTs have reported that they have not been making as much in charges, leaving many with a shortfall.
The Citizens Advice report acknowledged this has been a problem and said extra money must be targeted at areas where there is a shortage of services.
The report was compiled from evidence given by nearly 4,000 of its clients, research on the 152 PCTs and government statistics.
It said that there had been "little evidence of any real growth" in services and in a quarter of PCTs no dentists were taking on new patients.
It said 2m patients - compiled from government estimates - could not get access to an NHS dentist, with most deciding to pay for private treatment, go on a waiting list or not get treatment at all.
It said some areas such as Hartlepool were spoilt for choice, while others including Blackburn had very poor access.
And it added people in rural communities were particularly disadvantaged as they had to rely on public transport, forcing them to take expensive, difficult and time-consuming journeys to reach a dentist.
The BDA poll found 85% of dentists believed the new contract had not improved access to NHS services and 97% did not think it had removed dentists from the "drill and fill" treadmill.
Susie Sanderson, chairman of the BDA, said the new contract was "failing both patients and dentists".
"The future of NHS dentistry is becoming increasingly fragile and we need action now before it shatters altogether."
Roger Goss, of Patient Concern, said action was needed.
"We believe dentists should be made to do a set amount of work for the NHS if they are going to be allowed to practice.
"It would not be popular, but it would help solve this crisis."
The Department of Health defended the new contract saying improvements were being made and the old system had to change.
"It was agreed by all that the old system of NHS dentistry was deeply flawed and had to be modernised," it said.
Health Minister Rosie Winterton said: "The overall picture is that, despite the speculation, the number of dentists is growing and rather than leaving they are actually keen to expand their work for the NHS - hardly indicative of a failing system."