Pearly whites

PUBLISHED : Tuesday, 02 January, 2007, 12:00am
UPDATED : Tuesday, 02 January, 2007, 12:00am


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.

No hydrogen peroxide is used in the Gentle Touch treatment, so clients can go to a salon for the whitening process. Using active chlorine dioxide, a blue tray is inserted into the mouth before the gel is applied. During the treatment, the mouth is aspirated, but the gel's odour and the dryness that can follow may make you cough.

Gel is applied to the teeth for five or more seven-minute sessions, and a cool light is placed above the mouth. Clients wear protective glasses. There's no pain, just a slight discomfort because the mouth is kept open most of the time. One treatment should give immediate results. Clients are then given a gel to paste on their teeth for the next 28 days at home. This must be applied before eating darker foods such as red meat or red wine, practitioners say.

Launched in Asia about three months ago, the treatment costs HK$1,990 and is available at the Elemis Day Spa, Beautiful Skin Centre, Elle Spa, Victorian Spa at Disneyland Hotel and Lane Crawford in Pacific Place. A luxurious spa beats the dentist's chair any day. Rob Kemeny, chief executive and founder of Gentle Touch, says his product is the only one on the market that doesn't use peroxide. 'The gel is so safe you could swallow it,' he says.

So far, there have been no reports of tooth sensitivity although side effects of using peroxide can include sensitivity, inflammation, swelling and bleeding gums. The Consumer Council recommends using these products under strict professional guidance.

Kemeny says clients can expect their teeth to be two to 10 shades lighter after the treatment, depending on how dark their teeth are to begin with. It also works on caps, crowns and veneers.

'Whitening only gets your teeth as natural as you had them when you were a child,' he says.

The colour of your teeth is largely due to genetics and other external factors. For example, the use of antibiotics as a child has been shown to darken teeth.

'Then it's eating habits,' Kemeny says. 'And the thicker the teeth, the more they will stain.'

Other treatments, such as Zoom! Advanced Power, will require a trip to the dentist. Due to be launched in Hong Kong this month, the HK$6,000-HK$9,000 treatment is the brainchild of Bill Dorfman, a Beverly Hills dentist. A combination of a hydrogen peroxide-based gel and an intense light are used in a procedure that takes less than an hour. Charts are used to determine the colour of your teeth, enabling you to compare the whitening effect afterwards.

Lips and gums are covered, leaving only the teeth exposed for the gel's application. A whitening light is then placed above the mouth, accelerating the gel. The product claims to be able to make teeth eight to 14 shades whiter.

Valerie de Marco, vice-president of Asia-Pacific operations for Zoom! Advanced Power, says that, after the treatment, fading should be less apparent. 'It will last forever if you look after it.'

Clients are given a take-home product. 'So long as they look after their teeth afterwards, they will always have the result,' De Marco says.

She advises that people stick to a so-called white diet for the first two days afterwards - that is, consuming food and drink that's lighter in colour.

The product won't bleach crowns or veneers, however, so if you have these at the front of your teeth, there may be a colour mismatch.

Dentist Belinda Poon says many Hong Kong practices offer whitening treatments. Hers has two, one of which involves putting a blue light over the mouth to activate a bleaching gel, for up to HK$10,000. She says many people feel sensitivity. 'We recommend really strong painkillers to take before the treatment,' Poon says.

She says that the effects of whitening treatments depends on the colour of the teeth before the product is applied. 'If your teeth have blotches of brown stains, you may not get them that white. You will get some whitening. If you want to have the whiter effect, you may have to do it for a longer period.'

Home kits such as Dr White Blue Tooth whitening system can be bought over the counter, and includes a blue light and gel combination. The treatment takes 15 minutes a day for a week.

Costing HK$2,600 and available from Harvey Nichols in Central, the kit includes a mouth tray, which is put in hot water to mould into the shape of your mouth. Gel is then placed inside the tray. A blue light, about 4cm in diameter, is then wrapped around the lips.