More than 9,000 people in parts of North Yorkshire are waiting to get an NHS dentist.
Figures released by NHS North Yorkshire and York show that 9,297 people were on a waiting list to get an NHS dentist in York and Selby alone.
A spokesman said tenders were being put out to find new dentists for the area.
John Renshaw from the British Dental Association said "mismatches" sometimes occurred between those on waiting lists and those actually needing dentists.
The figures showed that in Selby and York 10,505 people were waiting for an NHS dentist in October which dropped to 9,297 by January after some people were assigned to practices.
But in rural parts of the county the figures revealed that no one was waiting for provision while in Harrogate only 465 people were on a waiting list.
Lorraine Naylor, assistant director of strategy for NHS North Yorkshire and York, said: "Unfortunately we didn't have anyone who was suitable to win a tender in York and Selby; however, the good news is that they're going out to tender again."
She also said one of the biggest problems was when patients applied directly to a dentist for a place and failed to inform the NHS when they had secured one, thus remaining on the waiting list.
Ms Naylor said that practices in Monkgate and Selby would attend to anyone who required emergency treatment.
Mr Renshaw added: "There is clearly still a residual problem in York, and in Selby.
"What is causing the trouble here is a mismatch between the provision and a waiting list and I think the PCT [North Yorkshire and York Primary Care Trust] should get this waiting list sorted out, it's not being handled as well as it should be."