Will you want a Zeta-Jones smile after you read this?

Dentists warn of the dangers of using do-it-yourself bleaching kits

To visitors from America, the state of our teeth has always been as shocking as the British weather. But the country that inspired Austin Powers and his yellowing overbite is now experiencing a boom in teeth bleaching.

Britain has seen a five-fold increase in people - dubbed "bleachorexics" by worried dentists - demanding tooth-whitening procedures, as the nation embraces the prospect of gleaming, bright teeth.

This may be aesthetically pleasing. But now medical experts are warning that Britons in search of the perfect Hollywood smile risk permanent damage to their teeth, gums and even throats.

Dr Mark Hughes of the Harley Street Dental Studio, one of Britain's foremost cosmetic dentists, told The Independent on Sunday that the problem lay with the growing number of people addicted to using home kits to self-whiten.

"People are increasingly buying teeth-whitening products over the counter and over the internet," said Dr Hughes. "A lot of the foreign products available are new and haven't gone through any trials or official testing. They may have been put together cheaply, so could have overly aggressive amounts of peroxide in them. That can cause extreme problems with teeth and gums."

Dr Hughes said amateur bleachers often thought they were saving money by attempting the treatment themselves, but then ended up having to spend more to correct the damage they had caused.

"We find this a lot: people are buying teeth-whitening products over the internet, and then having to come in here and spend more money to put it right," he said.

Teeth whitening - popularised in part by celebrity exponents such as Catherine Zeta-Jones, Kate Beckinsale and Britney Spears - has an ever-growing, predominantly female, following. At the most extreme end, some of these women are already showing signs of addiction to the process.

Experts say this is just the latest high-profile symptom of an increasingly image-obsessed society. The teeth-whitening industry is already worth an estimated $2bn (£1.2bn) in the US alone - a rise of nearly 500 per cent since 2000.

There are three major teeth-whitening techniques currently available on the British market. The safest and most effective are either the expensive laser-activated gel procedure available on-site at dental surgeries or the nightly use of a specially moulded dental tray containing small amounts of peroxide prescribed by a dentist.

But it is the third and most widespread method - the use of privately bought products, such as loose-fitting dental trays, over-the-counter bleaching strips and toothpastes - that is causing the dental industry so much concern.

"There has been a massive recent demand for teeth whitening because society in general constantly wants to improve its appearance," said Dr Linda Greenwall, author of Bleaching Techniques in Restorative Dentistry and a London-based cosmetic dentist. "In a society like that, people with a better appearance get offered jobs quicker and get higher salaries - because of this, there's a constant quest to improve on nature."

According to Dr Anthony Zybutz, another London-based cosmetic dentist, the problems centre around ill-fitting trays, which have the potential to spill peroxide into the mouth itself.

"If the solution leaks out, it can irritate the gums and lead to jaw joint problems," said Dr Zybutz, who has a practice in Harley Street. "[If swallowed,] it can also burn your throat.

"This is something you need to have done professionally, not over the counter or the internet."

Additional reporting by Sara Wallis

THE DEVOTEE

Lynne Thomas, 33, is a self-confessed bleachorexic. After expensive laser-whitening treatment this year, she now regularly re-bleaches her teeth at home:

"I've just always wanted very, very white teeth," said Ms Thomas, a public relations director, who estimates she has already spent up to £2,000 on achieving this.

"They make me feel more confident and attractive, and it was worth every penny.

"The dangers do worry me, but they wouldn't stop me. My friends have all commented on how nice and healthy my teeth look, and I'm very pleased with them.

"A lot of people would rather go for Botox jabs, but having your teeth whitened changes your whole face. As far as I'm concerned, it's the ultimate anti-ageing treatment."