Warning over DIY teeth whitening kits that erode enamel

DIY teeth whitening kits sold in high street stores can damage enamel and increase sensitivity, dentists warn.

A study led by experts at the University of Manchester Dental school reveals the risks of using over-the-counter products.

european regulations mean teeth whitening treatments that contain hydrogen peroxide – a bleaching agent – can be provided only by qualified dental practitioners.

But other treatments, including those containing sodium chlorite or sodium carbonate peroxide, can be sold by any pharmacist to anyone walking in off the street.

The research team, writing in the British Dental Journal, said traditional bleaching treatments have 30 years of safety data, but little research has been done to show over-thecounter products are safe.

The experts tested five DIY products available in Boots and superdrug on freshly extracted teeth.

They found that the products significantly reduced the hardness of the teeth and substantially damaged dental surfaces.

researchers said three that were tested – Mr Blanc Teeth, Janina Ultra white and Brilliant 5-Minute Kit – contained sodium chlorite, which significantly reduced hardness and increased surface abrasions. A fourth, iwhite instant, containing a substance called ‘PAP acid’, produced a ‘distinct etching pattern’.

And another, called smile science, containing sodium carbonate peroxide, resulted in ‘morphological alternations of enamel surface’.

Lead author Dr Joseph GreenwallCohen said: ‘Not all bleaching products are the same and not all bleaching products are safe.’ he urged the public to ‘undertake more caution in selecting bleaching or whitening products they apply to their teeth’.

Professor Damien walmsley, of the British Dental Association, said: ‘The lack of clarity over chemicals used in over-the- counter and online products means you could be gambling with your teeth.’

The British Dental Bleaching society, which commissioned the study, said it was concerned over-the-counter products could be harmful and advised anyone wishing to have their teeth whitened to see their dentist.

superdrug declined to comment but a spokesman said it would be reading the study ‘with interest’.

A Boots UK spokesman said: ‘The safety of our customers is extremely important to us and we thoroughly assess all of our dental care products before we put them on sale.’