Pearly whites

AMELIA LEE DOESN'T smoke or drink wine, coffee or tea to excess. But for years, Lee has been conscious that every time she smiles, she flashes stained teeth.

After a few botched attempts to brighten her teeth with home-bleaching products, she tried the cosmetic route. One visit to the dentist later - and a few thousand dollars lighter - her smile was noticeably brighter, although not dazzlingly so.

'I could definitely see a difference ... but there was no way they were going to glow in the dark,' she says. 'It was a lot more subtle.' Lee opted for a cosmetic treatment that combines a hydrogen peroxide gel with an intense light source, one of several whitening options on the market that are seeing a surge in popularity.

For years, the potential hazards associated with bleaching agents made many people wary of whitening products. In 1996, Hong Kong's Consumer Council published a report warning that home products exceeded acceptable levels of hydrogen peroxide. Samples taken from whitening toothpastes and trays that are inserted in the mouth with a bleaching solution showed concentrations of 2.6 per cent to 10.4 per cent in seven test samples.

At the time, the levels were in excess of the 0.1 per cent limit under European Union directives. The EU's scientific committee on consumer products recently suggested the level should be increased to 6 per cent, although this recommendation has yet to come into force.

In the meantime, the number of products entering the Hong Kong market suggests that demand for whitening treatments is growing. Some require a visit to the dentist, while others are offered at spas and department stores, depending on the bleaching agent used. These will usually involve the use of an activation light, or laser. Once the bleaching agent is applied to your teeth, the light speeds up the action, enabling a whitening effect in hours, rather than weeks, as most home-bleaching products require.