The decision would have a "big impact" on Newtown, said the dentist

Their registration is to be cancelled by Newtown's Clifton dental practice on 1 December.

The surgery said the loss of a dentist and failure to find a replacement were the reasons for its decision.

But Powys Local Health Board said that it was trying to find a dentist to relocate to Newtown.

Chris Himsworth, who set up the practice in June 1996, said in a letter to patients: "I regret to inform you that your NHS registration with this practice will end three months from the date of this letter (1 September).

We have tried to attract another dentist to the practice but to no avail Letter to patients

"This decision has not been made lightly and was taken after careful consideration of all the options available at this time."

His letter said that a dentist's decision to leave the practice would have a "big impact on everyone" and meant that he was unable to continue to provide NHS care on his own.

"We have tried to attract another dentist to the practice but to no avail," said the letter.

"Insufficient government funding into NHS dental provision over many years has now resulted in dentists leaving the NHS on a scale never seen before.

"We have reached the point where quality of service and care would be compromised by shortening appointment times, seeing excessive numbers of patients and using the cheapest materials available and we find this unacceptable."

The practice has tried to attract another dentist but to no avail

Mr Himsworth, in the letter, went on to to say that "increasing bureaucracy and rigidity" of NHS regulations together with an uncertain future have compounded the situation.

Powys Local Health Board confirmed an NHS dentist had resigned from her post in Newtown.

It had resulted in NHS treatment for adults being suspended, but it did not affect NHS services for children, the health board added.

"This is very disappointing news, but the local health board is continuing to actively search for dentists to locate to the area," said a spokesman.

"We have had success in finding a dentist recently for Machynlleth and we continue to work closely with the Welsh Assembly Government to ensure that maximum use is made of the schemes the assembly has put in place to attract dentists into areas of shortage, like Powys.

"The difficulty in recruiting dentists is not unique to Powys but we do recognise that there are particular issues surrounding access to services facing people living in rural communities.

"We know that the assembly is aware of the difficulties faced by people accessing an NHS dentist living in certain areas of Wales.

"The assembly has taken steps to address this through the Welsh Dental Initiative which gives financial incentives to dentists willing to provide NHS dental treatment."

According to Assembly Government figures, over the last two years eight new practices have opened in Wales including in Machynlleth and Crickhowell.