If action needs to be taken we will drive it forward

John Vickers, Office of Fair Trading

It will also study the expectations and rights of consumers and the availability and quality of information for consumers to enable them to make informed choices.

The investigation, carried out in response to concerns raised by the Consumers' Association, will be completed by the end of the year.

OFT director general John Vickers said: "Our preliminary study has given grounds to suspect the market is not working well for dental patients.

"If action needs to be taken we will drive it forward."

The British Dental Association (BDA) has pledged to fully support the OFT inquiry.

Pricing guides

A spokesman said: "The BDA will wish to put forward its own evidence to this important issue, presenting the issues of private practice within the very difficult circumstances that are currently facing all dentists in the UK, working in both the NHS and private practice."

The BDA said it had consistently advised dentists to give typical price indications as a guide to the general charging levels in a practice.

"Patients should always be given a full treatment plan with costs prior to committing themselves to treatment," said the spokesman.

The BDA has also been calling for a dedicated complaints service that deals exclusively with dentists and an extension of NHS procedures to cover private dentists.

The British Dental Health Foundation (BDHF) approves of the investigation.

Greater transparency

Its chief executive Dr Nigel Carter said: "Most dentists carrying out private treatment offer a fair deal.

"However, it is in the interest of the patient and the dentist that a system is created that is more transparent to the public."

The foundation advises patients to shop around for the best value and always obtain a written treatment plan and cost estimates before treatment is started.

The Consumers' Association has welcomed news of the investigation.

Director of Consumers' Association Sheila McKechnie, said: "This is great news for consumers.

"It is right that the OFT should act.

"They are investigating the whole dentistry market, based on initial research from Which? and Health Which?, and our campaigning activity.

"We will work with the OFT in whatever way we can to help their investigation, and we look forward to actions that will improve this market for consumers."