Everything you need to know about teeth whitening

26 June 2017
By Fashion Quarterly

Teeth Whitening

The journey to a pearly smile no longer breaks the bank — or your teeth.

In a nutshell

“Teeth whitening is a bleaching process,” explains Katherine Marshall, founder of Brighter Smile whitening clinics. “What we’re doing is removing surface staining to bring your teeth back to their natural whiteness.”

Although teeth whitening has previously been linked to sensitivity and gum damage, the whitening products used today are much less harsh, and tooth sensitivity — although still a possibility — isn’t as common. “Carbamide peroxide [the ingredient most often used] is a lot gentler on your teeth,” says Katherine. “It doesn’t matter as much if you get it on your gums, so it’s also safer for at-home use.”

In the case of in-clinic whitening, high-strength peroxide is used. At-home products aren’t as strong but are applied more often and left on for longer. As to how white you can go, it depends how porous your teeth are and what you were born with. “The whitening process will only go as light as your natural tooth colour, so you’re never going to have a fake ‘Ross from Friends’ smile,” says Katherine.

In chair

Most dental practices offer an in-chair whitening service, and although it’s a lot cheaper than it used to be, it’s still the most expensive option, at around $400-$600. High-strength peroxide is painted onto the front of the teeth, then activated with an LED light in order to speed up the lightening process.

For those who have undergone a lot of dental work or have teeth or gum problems, Dr Amanda Johnston of Purely Dental says it’s best to have your treatment done by a pro. “During tooth whitening, the enamel structure is changed, which can complicate further dentistry immediately following the treatment,” she explains. “Your dentist is usually able to work around this during your treatment plan.”

In-chair whitening is also offered by specialty treatment clinics such as Brighter Smile; the treatment is the same, although a lower-strength peroxide is used. “The stronger the gel you use, the greater the risk of teeth sensitivity, so we use a gel comprised of a gentle peroxide and a catalyst, which gives you a similar result without any pain,” says Katherine.


The gel is reapplied twice during the treatment to maximise its effectiveness. You can generally expect to go up to 12 shades lighter, although results vary from person to person. A one-hour session will cost around $200.

Both Amanda and Katherine recommend in-chair whitening as a great solution for those looking for results right away, although it’s a good idea to get the treatment a while before a big event to allow for a second session, if required.

At home

If you’ve got the time, a slower approach to whitening is best. “Usually better long-term results are achieved using gradual at-home treatments in trays provided by a dentist,” says Amanda. “However, it takes longer and requires commitment.”
At-home treatments comprise a set of whitening trays (similar to mouthguards) and a peroxide lightening gel. The gel is inserted into the trays, which are then worn for one to two hours a night for two weeks, or until you reach your desired shade. Type ‘teeth whitening kit’ into your Google search bar and you’ll be bombarded with thousands of products at a vast range of prices. However, not all kits are created equal and, in fact, some can do more harm than good.

“At-home treatments vary,” says Katherine. “There’s a lot of stuff you can buy off the internet, and not to dissuade people from using them, but you do have to be careful, especially if you’re buying from overseas, as you don’t know the strength you’re using — you can damage your gums and enamel.”

“In New Zealand, the safety of dental products is carefully monitored, so most products are safe for most people, if they’re used as directed,” says Amanda. She and Katherine recommend buying locally from a reputable supplier, and if in doubt, checking to make sure they’re registered with the New Zealand Cosmetic Teeth Whitening Association.

“If someone is registered with the NZCTWA, then you know that they’ve been trained and that they follow the regulation guidelines,” says Katherine.

Some at-home kits also come with a mini LED light, although Katherine doubts they do much: “They’re more for show than anything else.” The safest and most effective kits are those that are custom-made by a specialist to fit your teeth. And although it’s cheaper to purchase kits that allow you to mould your own mouth tray at home, they’re not worth the few dollars you save. It’s difficult to get a self-moulded tray to fit precisely and there’s a high likelihood that the gel will get onto your gums, causing damage.

Most dentists and whitening clinics offer a custom tray service, which involves having your teeth cast in the clinic, and some also give you the option of a remote service in which
a teeth-casting kit is mailed to you, cast by you at home, then posted back to them to create in the lab. Regardless of which you go for, a set of custom whitening trays costs $150-$300. Many clinics offer a combo deal of a single in-chair session combined with fitted at-home trays, which is good for those whose teeth are heavily stained.

“A lot of people choose this because they can get the whitening started off in-clinic, then go home and use the kit to get their teeth to the desired shade,” says Katherine.

On the brush

And as for whitening toothpaste? Most specialists recommend you don’t bother. “Some toothpastes contain whitening chemicals but may not be strong enough to effectively change the tooth colour,” says Amanda.

“What it’s doing is scrubbing the stains off your teeth manually, which can be quite abrasive, and you’ll find a lot of people get sensitivity because of this,” says Katherine.

When it comes to preventing stains, Amanda says the best way to keep your teeth white is still the old-fashioned one — with toothbrush, floss and a classic fluoride toothpaste. But if it’s the movie-star smile you’re after, you’ve got to bleach your teeth to fabulous.

Words: Bronwyn Williams

This article originally appeared in the Autumn 2017 issue of Fashion Quarterly.

Subscribe & Become an FQ VIP

As a Fashion Quarterly subscriber you enjoy exclusive content, giveaways, invitations to VIP events, and more.

Subscribe & Become an FQ VIP

As a Fashion Quarterly subscriber you enjoy exclusive content, giveaways, invitations to VIP events, and more.

Sign up to the FQ newsletter and WIN*

Get the latest fashion, beauty, and lifestyle news delivered straight to your inbox each week.

*Ts&Cs apply.

Find out more at fq.co.nz/fq-newsletter