Patients may have to resort to emergency care, or find an alternative practice, because their dentists have fulfilled their annual contracts too soon.

The Department of Health has warned primary care trusts to have 'clear lines ready in case of media interest' if patients are left without a dentist in the closing weeks of the financial year.

Under the terms of the new contracts, dentists agree to provide a number of 'units of dental activity' (UDAs) for a certain price over the course of the year. Treatment is split into three categories. A dentist earns one 'point' for simple investigative work, three points for more complex work, such as fillings, and 12 points for treatment involving laboratory work, such as crowns and bridges.

A DoH memo sets out how PCTs should deal with patients of dentists who complete their contracted work before the end of the financial year - and will not be paid for any more NHS work.

The letter says PCTs must 'ensure patients know how to access urgent care, and publicise any spare capacity in other dental practices locally'. It also tells PCTs to be ready to respond to media reports about the problem, saying they should have 'clear lines ready in case of media interest'.

Primary care dental staff contacted by HSJ suggested that a small number of practices in each area are likely to be hit by the problem.

Bradford and Airedale Teaching PCT said 10 of its 73 dental practices were in danger of completing their contracted work too soon. The PCT aims to avoid NHS patients being refused treatment by introduce a pooling system, with other dentists with spare capacity taking on extra work.

Cornwall and Isles of Scilly PCT primary care support agency director Adrian Tyas said early completion of contracts was a problem in a 'small number of cases' in his area. Those practices in danger will be monitored weekly in an attempt to ensure that they do not complete their contracts early.

British Dental Association chief executive Peter Ward said the dental contracts introduced last year had effectively introduced targets, which dentists would make sure they hit, rather than risk underperforming. This meant that some would finish their work earlier in the financial year than planned.

'What was initially meant to be a performance measure translated into a target when contracts were drawn up,' he said.

Mr Ward also said that the levels of contracted work often differed significantly from the historical levels of work dentists had performed.

A poll of BDA members, taken after the contracts were drawn up, revealed that 75 per cent of dentists thought the UDAs they were contracted to provide 'were not relevant to their real level of work'.

Another problem with the NHS dental contract hit the headlines last month, when it was discovered that patients were being turned away from some dentists because of a shortfall in primary care trust dental budgets.

The problem has come about because many dentists are seeing more 'exempt' patients than predicted. Such patients, including children, make no contribution towards their treatment. The result is that PCTs around the country are reporting significant shortfalls in their expected patient income.