The NHS urgently needs more dentists in Scotland

Ms Brankin said she was "appalled" by the behaviour of Kenneth Barr, who is introducing a private membership plan.

But the Stranraer dentist said he did not have any political ties and that he had taken legal advice over comments which he believed were defamatory.

The British Dental Association said there was a dental crisis in Scotland.

Hundreds of people queued outside Mr Barr's surgery earlier this week to try to join his scheme.

Speaking during a Holyrood debate on access to dental services, Ms Brankin said: "Frankly I was appalled by the behaviour of that dentist and it seemed to me to be no more than a political stunt.

'Patients deserve more'

"It's not good enough for the people in Stranraer to be treated in that way.

"It's not good enough for dentists to be able to train at the expense of the public purse to build up an NHS list, to build up the trust and the confidence of patients in Stranraer and then to walk away.

"Patients deserve more than this."

The Scottish National Party said the minister should not criticise individual dentists for deciding to go private.

After careful consideration of all the issues a decision was made to move a group of my patients away from the NHS Kenneth Barr

SNP health spokeswoman Shona Robison said: "I don't think the intemperate language used by the minister in attacking the dentist in Stranraer, who has left NHS dentistry, is all that helpful.

"We need to persuade dentists to remain working within the NHS and I really think persuasion is the way to go forward, not an attack on individual dentists."

Alex Fergusson, Tory MSP for Galloway and Upper Nithsdale, said his constituents felt "a great depression" over NHS dental provision.

Ms Brankin said it was "simply not good enough" that a small number of dentists were turning their backs on the NHS to work in the private sector.

However, Mr Barr told BBC Scotland's news website that he was retaining a "large number" of NHS patients.

Rhona Brankin criticised dentists moving to the private sector

He said he had been dealing with the company which will administer his private scheme since January.

"After careful consideration of all the issues a decision was made to move a group of my patients away from the NHS some considerable time ago," he said.

"I want to make it perfectly clear that I have no political motives, allegiances or affiliation and I believe some of her quotes are defamatory.

"I have sought advice and I will take any necessary action to protect my practice, my patients and my professional reputation."

However, under section 41 of the Scotland Act, any statement made in parliament is protected by absolute privilege.

Missed opportunity

Last month the executive announced a �150m funding drive to modernise NHS dentistry in Scotland.

However, Dr Andrew Lamb, director of the British Dental Association in Scotland, said it was a missed opportunity.

"There is little doubt that there is a dental crisis in Scotland, one that has been brought about by chronic under-investment in NHS dental services and lack of funding for training," he said.