A week before the budget, the government faces more pressure to expand public dental services and the fallout from an unprecedented outcry from dentists over their treatment by Medicare.

The state of public dental services has reached a ''horrifying'' state, the Consumer Health Forum says in a public campaign it launches today pressing for government action on the 650,000 people with dental problems who wait an average two years to get treated.

It remains unclear whether the government will meet the Greens' demand to honour its pledge to make a start in next week's budget to establish a ''Denticare'' scheme.

The campaign comes as government officials face a grilling at a Senate committee inquiry today into the pursuit of dentists accused of failing to meet documentation requirements in claiming payments under the Medicare chronic disease dental scheme.

More than 200 dentists are estimated to have written to the inquiry to strongly criticise being targeted for what they say is unjustified demands for repayment of money for failing to file the required paperwork for services which they had carried out correctly and in good faith.

The government has estimated that more than $21.6 million has been claimed outside the rules, with 65 dentists found to be non-compliant.

But the government has received just $259,427 back from dentists who have received demands for repayment.

The Minister for Human Services, Kim Carr, would not comment yesterday on what measures the government would take to recover the money, saying it was inappropriate to comment before the Senate committee hearing.

Shane Fryer, the president of the Australian Dental Association, said he had never seen such widespread criticism from dentists of a government measure.

The reaction, he said, was likely to weaken dentists' confidence in any future government dental schemes.

The chief executive of the Consumers Health Forum, Carol Bennett, said it was ''appalling'' that only 11 per cent of people actually received any dental treatment in any one year.

Under the forum's proposals, dental hygienists and therapists would be able to expand their scope of practice.

There would be prioritised access to dental treatments through targeted schemes for those who needed it most.