Access to state-funded dentistry on the National Health Service in England is "deteriorating" after a radical shake-up of the system pushed through against dentists' wishes, a committee of MPs said on Wednesday.

The government made the changes to improve access, but the number of patients seen by NHS dentists had actually fallen by 900,000, the House of Commons Health Committee said.

Complex treatments, such as crowns and bridges, had halved, while the number of tooth extractions had increased.

"The reason for the decline in the number of complex treatments since 2006 has not been explained satisfactorily and we are very concerned that some patients do not receive the quality of care they need within the NHS," the Committee said in a report.

"There is no evidence for the Department (of Health's) claim that the decline is to be explained by more appropriate simpler treatments.

"Various measures of access all indicate that the situation is deteriorating," it warned.

A new contract for dentists introduced in 2006 was meant to remove the postcode lottery of NHS access that saw huge queues form when new practices were opened in poorly covered areas like Scarborough.

Local health authorities were given responsibility for making sure sufficient dental services were available.

The way patients were charged and dentists paid was changed to remove the previous "drill and fill" system of payment per item of work completed.

Instead dentists were offered a guaranteed income in return for completing a quota of dental work - but many disliked the new contract and opted to go fully private instead.

The committee said it was "extraordinary" the government did not pilot or test the new payment system first.

It said that because the price changes made some treatments, like a single filling, more expensive, some low-income patients were now waiting till they had a number of dental problems before visiting the dentist.

The government's Chief Dental Officer Barry Cockroft said many local health authorities were investing in new dental services but that it would take time for the new system to deliver its promised improvements.

He told BBC television the access data used by the committee was retrospective and did not reflect the current position.

"We are much more concerned about what is happening now and going forward, and we are much more confident about the future," he said.