Dental treatment in England is the most expensive in Europe, a survey shows.
NHS dentistry was reformed two years ago
The poll of nine countries found the total cost of a filling - to the NHS, not what the patient pays - was £117 in England compared to £6 in Hungary.
The findings of the study, led by the Erasmus University Rotterdam, in Holland, are mostly do to with variations in the cost of living.
Dentists said the Health Economics journal report was flawed as it was not comparing "like with like".
However, the findings still pile more pressure on NHS dentistry which has been criticised following the introduction of a new contract in 2006.
The deal was meant to entice dentists back to the NHS but has so far made little impact, with 2m patients complaining they still cannot get access to services.
And it comes as an ever-increasing number of people from England go abroad to have dental treatment.
Researchers looked at costs from things such as x-rays, materials, drugs, overhead and dentist pay.
NHS dentistry is subsidised by the state with patients contributing to the cost of treatment. In the case of fillings, patients in England contribute £43.60.
England was followed by Italy and Spain as the most expensive places.
Lead researcher Siok Swan Tan said the differences were primarily to do with the increased costs in certain countries.
"Labour costs were the most important cost driver in all practices, comprising 58% of total costs.
"Overheads costs were the second most important cost component in the majority of countries."
Peter Ward, of the British Dental Association, said the report was flawed as the dentist surgeries quizzed in England tended to have a high number of special needs patients.
"It is a very small sample, it is not representative and it is not comparing like with like.
"It is impossible to make a sensible comment on flawed data."