Is whitening toothpaste simply a waste of money?

When it comes to that million dollar movie star smile, everyone knows only one colour will do: bright white.

Yes, for those committed to looking perfect, a set of shiny white teeth is a must-have accessory. As such, a range of treatments and products are available to get those pearly yellows white. In-office whitening treatments are the most effective, but also the most expensive, and even store bought whitening treatments can cost more than $100, so many of us opt for a more low-cost option: whitening toothpaste.

The question is, do they work? A new investigation conducted by British newspaper The Daily Mail has found that none of the six whitening toothpastes they tested had any affect on tooth colour.

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First, the paper had the tooth colour of six women in their 30s and 40s professionally assessed by a dentist. Then they had the women brush with a whitening toothpaste for a month.

The toothpastes tested were Arm & Hammer Advanced Whitening Toothpaste, SwissDent Xtreme Whitening Toothpaste, Oral B 3D White Enamel Protect, Beverly Hills Natural Whitening Expert, BlanX Intense Stain Removal, and Rembrandt Complete Whitening Mint.

Any whitening effect that these types of pastes have is likely due to abrasive additives rather than the bleach they contain, reports the Los Angeles Times. For example, Crest 3D White Vivid contains tiny hydrated silica particles, which scrub the tooth surface clean. Though some pastes also contain bleach, experts say it has no effect, because it is rinsed away before it has a chance to act.

The results of the Daily Mail's month long test? There was no perceptible change in tooth colour in any of the test subjects, regardless of which paste they used.

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So, why can toothpastes claim they are whitening?

“Any toothpaste can claim to whiten teeth,” says Advertising Standards Canada spokesperson Nicole Bellam. “They’re allowed to claim that, even if it’s just by mechanical action.”

She explains that according to Health Canada’s Guidelines for Cosmetic Advertising and Labelling Claims, even if a toothpaste contains no bleach, an active whitening agent, or an abrasive that helps scrub the tooth clean, it can still claim it is a whitening toothpaste.

“Even regular flouride toothpaste can make that claim,” says Bellam.

There are, however, rules around exactly how these claims are made. For example, a toothpaste can claim that it “whitens” or “brightens” teeth, but it cannot claim that it “bleaches” teeth.

The lesson here? Use a whitening toothpaste if you must, as it may be giving your teeth an extra scrub. Just don’t expect miracles.