Patients may have to travel across Birmingham to makeshift "toothache clinics" if too many city dentists opt out of their NHS contracts in April.
So far only 19 of the 173 practices have applied for new contracts, and another 56 have expressed interest ahead of the March 31 deadline.
But members of the city council's health scrutiny committee yesterday expressed concerns over the primary care trusts' plans to set up temporary centres to treat NHS patients once the new contracts and three-tier pricing come into effect on April 1.
Ros Hamburger, consultant in dental public health for the four Birmingham PCTs, yesterday said she was confident an NHS dental service will still be provided.
She told councillors: "We want to carry on working with dentists who we know and trust but if some do leave the health service we have the cash to buy in further services.
"A number of city dentists have contacted us saying they would like to grow their practices, and obviously they will receive more money for that. If that doesn't work we would look at providing some dental services by setting up new practices in affected areas, but we believe this won't happen. "
Dentists could treat patients in existing facilities on a short term basis, but this was just a contingency plan.
She said: "However that is not our Plan A, it's Plan Z, but if that situation arises we believe we're prepared for it. We could set up a 'toothache' service, but that would be for a couple of months - but this is Plan 99, a last resort."
Coun Deirdre Alden (Cons, Edgbaston), added: "I don't think a 'toothache clinic' is a good enough dental service for our community."
She also criticised the clarity of a new three-tier pricing system, claiming it would encourage people to "stack up" problems until they could afford treatment.
From April 1 an examination and polish will cost NHS patients £15.50, fillings will cost £42.40, while complex work will attract a fee of £189.