It is hoped Polish dentists will help bridge the dental gap

The criticism came as ministers welcomed the arrival of the first 11 dentists from Poland.

The Scottish Executive said a total of 40 Poles had been recruited to join the NHS this year.

Scots in many areas have struggled to find an NHS dentist partly because increasing numbers of practices have opted out of the health service.

Dental leaders have also rejected a multi-million pound scheme to encourage more practices to treat NHS patients.

The British Dental Association (BDA) warned the executive's incentive scheme to encourage practices to carry out NHS treatment would have the reverse effect.

To qualify for allowances, practices are required to have at least 500 registered NHS patients per dentist - at least 100 of whom must be fee-paying adults.

The Polish dentists will play a valuable role in increasing the number of patients who are able to choose to access NHS dental services across Scotland Lewis Macdonald Deputy health minister

But the BDA's Scottish committee said the "target-driven" qualifying criteria would mean more practices might abandon all health service patients to focus solely on private work.

Instead it is calling for "a more equitable sliding scale". This would mean all dentists treating NHS patients would be eligible for the allowances, and those with the greatest commitment would be eligible for higher levels of payments.

BDA Scotland director Dr Andrew Lamb said: "The intransigence of the Scottish Executive threatens to jeopardise patients' access to NHS dentistry.

"There are many dentists, across Scotland, who are committed to their NHS patients and want to continue treating them.

"Sadly, the approach of the Scottish Executive will make it increasingly difficult for some of these practitioners to continue doing so."

Deputy Health Minister Lewis Macdonald, who met the Polish dentists on Monday, insisted the executive had no intention of reviewing the qualification for allowances introduced last October.

Patient threshold

He said: "The main problem of access to NHS dentistry is for adult patients who are de-registered against their will and then forced to pay for private treatment.

"For us to invest money without setting a threshold for the number of adult NHS patients a dentist must treat would compound this problem, not solve it."

The first group of 11 dentists from Poland will deployed in Fife, Forth Valley and Argyll and Clyde.

In total the 40 Poles will provide treatment for around 80,000 patients.

Mr Macdonald added: "It is clear the Polish dentists will play a valuable role in increasing the number of patients who are able to choose to access NHS dental services across Scotland.

"That is good news for patients and good news for the future of NHS dentistry in Scotland."