The overhaul of NHS dentistry is still facing major problems on the day it comes into force, health bosses say.
Many dentists are unhappy with the new arrangements
The NHS Confederation poll of 124 of the 300 senior local health chiefs in England found many thought the new arrangements were causing uncertainty.
The primary care trust chief executives also said some dentists may stop providing NHS services in the future.
A new contract and fees system is being introduced by the government on Saturday in a bid to improve services.
Dentistry has long been a thorn in the government's side with many people claiming they cannot find an NHS dentist.
About one in 10 practices do not accept new patients and over recent years images of people queuing in the street to register with new dentists have become familiar.
The reforms which are coming into place are meant to introduce a simpler system of fees and reward dentists for carrying out more preventative work.
But dentists have complained the deal does not live up to expectations with about 10% thought to have refused to sign up to it.
And the survey by the NHS Confederation shows the organisations responsible for administering the new contract, the PCTs, also believe it is fraught with difficulties.
PCT chief executives said that while the majority had secured enough provision to meet the demand from their local population, there was a risk that more dentists could walk away from the NHS in the future.
The survey revealed that 5% of dentists could stop providing NHS services to children, while 6% could walk away from running adult care.
The NHS Confederation, which represents health service managers, said a review of the contract may be needed after a year.
NHS Confederation chief executive Gill Morgan added: "While it is clear that recent headlines predicting the end of NHS dentistry are wrong, there are still significant problems on the day the new contract comes into force."
The survey comes as a poll of 855 people by the consumers' association Which? revealed more than three-quarters thought it would become harder to find a dentist under the new arrangements.
Four out of five also said they did not trust the government to improve dentistry in the next year.
Which? campaigner Sara Apps said: "The government has lost public trust in delivering accessible dental treatment to all."
Health Minister Rosie Winterton said the public could be confident in the future of dentistry.
"It is good news that the majority of NHS managers are confident these reforms will allow them to provide dental services that truly reflect local needs.
"That is the intention of the new contracts and already many PCTs are showing how this is turning around dentistry at a local level."