MOVE OVER, BOTOX INJECTIONS and oxygen shots, cosmetic dentistry is the latest 'in' treatment. A perfect row of dazzling white teeth is no longer the exclusive domain of America's rich and famous; now lesser mortals can have their stained, chipped gnashers transformed into a glow-in-the-dark Hollywood-esque grin. Gums can be lasered into regularity, crooked incisors straightened with state-of-the-art braces, front teeth elongated with veneers (supposedly to make you look younger) and the whole lot given a pearly white makeover in an hour. So popular have they become that cosmetic dentists in the United States, or prosthodontists as they're technically known, are taking over from make-up artists, hairdressers and personal trainers as the new celebrities of the beauty world. With many people in Hong Kong suffering from badly stained, irregular teeth due to poor diet, general neglect and the effects of tetracycline (an antibiotic which can cause coloured stripes to form on teeth), the popularity of cosmetic dentistry has snowballed, with whitening processes being the most sought after. There are two types of technique available in Hong Kong: home bleaching, currently the most common method, and in-clinic whitening (that is, at the dentist's surgery). At the start of the former treatment, the dentist takes an impression of the teeth and then custom-makes an upper and lower 'tray'. Once at home, you fill each 'cup' in the trays, corresponding to each tooth, with a hydrogen-peroxide gel. The length of time you need to wear the trays and the concentration of the peroxide solution is determined by the dentist, who will have evaluated the amount of whitening your teeth need from the outset. Unless staining is severe, most people wear the trays for four to seven hours a day or night - not surprisingly, the majority opt for the latter - for about two weeks. It is supposed to make teeth noticeably three to four shades whiter and, at about $4,500, is the cheapest whitening method around. However, because it can cause acute sensitivity, it has a high drop-out rate. 'I had to stop wearing the trays after the third day because my teeth became very sensitive,' says local stockbroker Sarah Chessis, who had her teeth whitened several months ago. 'So I gave them a rest for a couple of days, then used the bleaching guards again. You don't have to wear them continuously and although I ended up wearing them for about a month rather than two weeks because of the breaks, the treatment still worked. In fact, it made a massive difference to the whiteness of my teeth - I'm delighted.' If you don't fancy the idea of DIY, get the dentist to do all the work. The latest in-surgery whitening treatment is BriteSmile, which was launched in Hong Kong in December. Invented by Dr John Warner, former Nasa scientist and inventor of the original Lasik eye-lasering machine, this involves the application of a hydrogen peroxide-based whitening gel on the surface of the teeth. Precisely calibrated cool blue light is shone on the gel-covered teeth for three cycles of 20 minutes, activating the whitening compounds and leaving teeth an average of eight shades whiter. 'The technique is safe, not least of all because it is performed and wholly supervised by trained dentists rather than leaving the patient to their own devices,' says Dr Brian Tang, who was recently in Hong Kong from the US to train dentists how to perform the BriteSmile technique. 'It won't corrode your teeth, scratch the enamel or hurt your gums. It won't damage veneers, crowns or fillings - but nor will it whiten them. So you might have to think about replacing them to match your new white smile.' Some patients experience slight sensitivity during or immediately after the treatment due to dehydration and the removal of what's known as pellicle saliva, which coats your teeth. The sensation goes away after 48 hours when teeth rehydrate and the pellicle layer returns. Because teeth absorb colour without the pellicle layer, says Tang, stay off cigarettes and dark-coloured food and drink such as red wine, soy sauce and coffee for 24 hours, or risk staining your newly acquired pearly whites. And if you manage to cut the stain-makers out of your diet as much as possible - and at about $8,000 for the treatment most people seriously consider it - results can last for two to three years. 'BriteSmile has proved very popular here and I think it will take off even more,' says Tang. 'It's definitely the way forward for teeth whitening.' Most adults would rather stick with their wonky teeth than go for metal train-track braces, but the new Invisalign technique makes teeth straightening a much more viable - and aesthetically pleasing - option. After the dentist sends a plaster impression of your teeth to Invisalign, the company creates a 3-D digital image. A computer program called ClinCheck maps out the movement of your teeth - from how they are to how you want them to be - and then uses laser scanning to build a series of transparent plastic models, called aligners, of each stage of the treatment plan. You wear each set of aligners - they look like a refined sports mouth-guard and clip tightly over your teeth - for at least 20 hours a day, removing them to eat, drink, brush and floss. They move the teeth gradually but gently and you swap them every fortnight for the next slightly modified set until the smile of your dreams is achieved. 'Like both fixed and removable dental appliances, the principle of Invisalign is to exert a suitable force on teeth, moving them to a planned position,' says dentist Dr Cecilia Young. 'The technique is safe, comparatively good-looking [stand a metre away from the wearer and you won't see the aligners] and they can be taken off during important meetings or occasions. Its success rate is good for suitable patients.' Unsuitable cases include anyone who suffers from crowded teeth or jaw discrepancy; the technique is also expensive and may vary from clinic to clinic, so it's worth obtaining several quotes for the treatment. Depending on the degree of malpositioned teeth, the alternative to Invisalign is corrective veneers. A thin shell of plastic or porcelain that is bonded to teeth to alter their position if necessary, lengthen, straighten and even them out. Teeth are first roughened and shaped - unlike crowns, only a minimal amount of natural tooth is removed - and a mould is made of your mouth, which serves as a precise guide for the shaping of the veneers. At the next appointment, the veneers are bonded to your teeth with an adhesive, and hardened with a harmless high-intensity light. 'It's a very refined procedure and differs from case to case,' says Young. 'As with all cosmetic dentistry, it is important that all patients seek proper consultation with reliable and skilful dental surgeons.' Veneers are said to be durable, virtually painless to place and easy to maintain. The biggest drawback is price - about $4,500 a tooth - but it depends on each individual case. You'd be forgiven for thinking that once you'd got your teeth straightened and whitened your mouth would be sorted out. If you're really after the perfect set, think about getting your gums lasered. The gingivectomy, as the procedure is technically known, corrects and reshapes the soft tissue (gingiva) around the teeth to improve its natural appearance. Although this operation can be carried out with a surgical knife, the latest technique uses a high-energy laser beam, which decreases post-procedure bleeding. 'Patients should be assured of both methods,' says Young. 'Gum bleeding is due to inflammation of the tissue and after a traditional surgical gingivectomy it is mild. It may seem a lot because it is usually diluted with saliva.' It may all sound like pure vanity but those who have invested in a mouth makeover speak of increased confidence. 'My teeth were stained and uneven and I never liked to show them when I smiled,' says accountant Grace Leung, who had hers whitened and straightened earlier this year. 'Although there were times when I wondered why I was spending so much money on something that wasn't exactly enjoyable, I'm glad I did it. Everyone comments on my improved appearance - some people think I've had a facelift - and I feel it really has changed my life.' adele@scmp.com Ask your dentist for further details of these treatments; for information about BriteSmile call the customer hotline on 2155 9880 or visit www.britesmile.com .
