Almost one in five dental students plans to shun NHS work completely, a study has suggested.
There have been concerns that access to NHS dentistry is limited
The results suggest a new contract designed to make NHS work more attractive has had limited success.
The University of Dundee-led study reported in the British Dental Journal found 18% of final-year students planned to stick to private work.
In contrast, of the 141 students questioned, just 3% planned to work solely for the NHS after graduating.
Some 79% of students planned to split their career between the NHS and the private sector, according to the survey.
A similar poll of first-year dental students carried out two years ago also found levels of interest in an NHS-only career were very low.
However, the proportion of respondants who planned to work exclusively in the private sector was just 7.5%.
The latest poll, of students at the universities of Dundee and Manchester, found about 60% planned to retire or cut down on their workload before the age of 60.
More than half said they would take time out of the profession once they started their families.
Lead researcher Dr Fiona Stewart said: "If these career intentions are followed through it could impact significantly on the future clinical commitment available to the NHS, and in our view these intentions should be taken into account for future dental workforce planning."
Peter Ward, chief executive of the British Dental Association, said: "This research confirms what we already know; that the great majority of young dentists aspire to work in the NHS.
"Whether the NHS will be able to provide them with jobs is another matter. The reality is that the new dental contract in England and Wales has restricted the amount of dentistry that primary care trusts and local health boards are able to commission.
"According to the government's own estimate, approximately two million people who wish to access NHS dentistry are unable to do so. It would be regrettable if young dentists were denied the opportunity to provide that care."
Labour MP Kevin Barron, of the Commons health committee, has said dentists have a "moral obligation" to give the NHS more as it costs £175,000 to train them.
Figures from the NHS Information Centre show NHS dentists on average now earn about 52% of their income from private patients - the first time private work has accounted for a greater share.
The government introduced a new NHS contract for dentists in April 2006 giving them 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.
A Departmental Health spokesman said NHS dental provision was "looking very healthy".
"It is important to remember that virtually all dentists mix NHS/private work during their careers and always have done.
"The new system of dental contracting in England means that a dentist reducing his NHS commitment to do more private work does not reduce the availability of NHS dentistry, as the local health service now holds a budget to replace any service loss."