Dentists are earning more from their private work than NHS patients for the first time, figures show.
Dentists' private work has been growing for some years
Last year they took home 48% of their gross income from NHS work, compared to 54% the previous year.
The average pay for dentists who run their own practices once expenses were deducted was £105,000, the official NHS data body, the Information Centre said.
It comes as many struggle to find an NHS dentist, but dentists said they were not turning their back on the NHS.
The figures relate to the 2004-5 financial year - before the new dental contract came into force.
From this April, the way dentists have been paid has been changed, although it was not accompanied by a significant rise in pay.
The deal was arranged in a bid to increase access to dental services, although not all dentists signed it, either retiring or devoting themselves full-time to private work.
And the Patient Association said it has not had a noticeable impact in many areas.
"The availability of NHS dentists is worrying for a lot of patients."
Over 90% of dentists do a combination of private and NHS work - a figure which has been growing since the early 1990s.
The figures from the Information Centre showed that one in 10 dentists earned more than £100,000, although the average for those not owning their own practice was £57,000.
Lester Ellman, of the British Dental Association, said it did not necessarily show that dentists were walking away from the health service.
"The demand for private dental care in the UK has grown over the last 10 years as more sophisticated and complex treatments become available.
"NHS dentistry now faces a period of great uncertainty and we are monitoring carefully the impact on NHS dental care for both patients and dentists.
"These figures relate to a period before the new NHS dental contract was introduced this April."
He believes it is too early to tell whether the new contract will shift this balance between private and NHS work.