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What's in HiSmile teeth whitening kits?
Each HiSmile teeth whitening kit comes with enough gel for six applications, an LED light, a mouth tray, a shade guide and an instruction manual. You apply the gel to the mouth tray, insert it, attach the LED light and keep it on for 10 minutes. Afterwards, you rinse your mouth out with warm water.
The ingredients in the gel include:
- Sodium bicarbonate (5%)
- Sodium chlorite (1%)
- Citric acid
- Aloe leaf juice, pomegranate seed extract, chamomile flower extract, glycerol, propylene glycol, deionised water, carbomer, xanthan gum, menthol.
Does HiSmile work?
Whether HiSmile works or not will largely depend on why your teeth are stained, says Professor Laurence Walsh, president of the Australian Dental Association's Queensland branch.
If the stains on your teeth are difficult or ingrained, it's unlikely to work. But if your issue is with surface stains, such as those from coffee, tea, red wine, berries or sauces, HiSmile may strip their colour, leaving you with less staining on your teeth.
However, Walsh says the idea that your teeth will be eight shades whiter is laughable, and you'd likely get similar results from a supermarket product – with more bang for your buck.
Is HiSmile safe or will it damage your teeth?
HiSmile claims its products are safe and have been "specially developed to ensure that you will not encounter any sensitivity". But Walsh thinks there's cause for concern.
"I have seen many patients in my practice who have damaged their teeth by using bleaching products at home without seeking professional advice," he says.
The Australian Dental Association is particularly concerned about the fact that HiSmile contains citric acid and sodium chlorite:
- According to research, citric acid can erode tooth surfaces and cause sensitivity. So applying HiSmile gel to your teeth, particularly over an extended period of time, "is likely to cause harm," says Walsh. "It is known to damage teeth when it sits in contact with them for a prolonged period of time."
- HiSmile gel also contains sodium chlorite, which can cause poisoning if ingested. "If you had a very strong solution of sodium chlorite, not necessarily what's used here, then that's certainly a problem," Walsh says. "It's regarded as a strong oxidant, and there have been reported cases of sodium chlorite poisoning." However, in this kit "the effective concentration by the sodium chlorite is very low", so unless you ingest large quantities of it, you'll likely be OK.
- Mouth tray Because the mouth tray is one-size-fits-all and not specially fitted, you may need to use a lot more gel to coat your teeth. That's problematic because it could hurt your teeth, and you could end up swallowing more of the gel.
- Overuse Consumers who buy HiSmile but are disappointed in its effectiveness could be tempted to use more of it or keep the tray in for longer to get the results they're after. Without a professional monitoring progress and tooth condition, they may end up damaging their teeth. "I'd be quite concerned that people will say, 'Oh it isn't doing much, I'll just keep using it for longer,' and then you run the risk of harm but no benefit," says Walsh.
Before and after magic
HiSmile's Facebook page is full of before and after videos showing seemingly miraculous results. So miraculous, in fact, that we got a little suspicious.
We asked Walsh whether he thought the before and after shots were realistic. His answer? "No."
"When I've seen products like this in the market before, and we've analysed what are claimed to be before and after pictures, they show little to no change or amateur manipulation using Photoshop," he says. "It's one of the concerns that we have. There are a lot of apps that will now alter the shade of teeth, but it's not a real change from the original result.
"I think this product is being marketed to a certain group using social media who won't be aware of the subtleties of the chemistry and the complexity of teeth whitening."
We asked HiSmile whether its videos had been manipulated in any way. The company refused to confirm or deny, but admitted "they specifically reflect the difference of eight shades whiter" and that consumers need to look elsewhere to see "actual results".
Translation: They aren't showing "actual results".
We spoke to the ACCC about whether companies are allowed to dramatise the effectiveness of their products in before and after pics. Unsurprisingly, the answer is no.
Businesses aren't allowed to say anything that could give consumers a false impression, says an ACCC spokesperson, and that applies to all their advertising, including on social media.
"If a business was digitally altering photos in 'before and after' style advertising, this may create a false impression to consumers about the efficacy of the business's product or service, and could be in breach of the Australian Consumer Law."
Right of reply
CHOICE reached out to HiSmile about their products' safety and efficacy claims:
- HiSmile didn't respond to our queries about citric acid.
- HiSmile claimed that the fact the gel has a "neutral PH level above 6" meant it wouldn't cause tooth sensitivity. That's wrong on several counts. Firstly, a neutral pH is 7.0 – anything below that is acidic. Secondly, even if the gel does have a neutral pH, it could still lead to mineral loss and sensitivity due to soft tissue irritant reactions to bleaching agents.
- HiSmile claimed the "patented" design of its mouthguards limited gel from leaking out and being ingested. We asked for evidence of the patent to explore further, but HiSmile didn't respond to that. Regardless, Walsh says that because HiSmile's tray isn't customisable "the fit cannot be ideal for all patients of all size or all dental arch shapes".
- We asked for evidence that HiSmile works to remove ingrained stains. The company said "there are clinical studies" that prove sodium chlorite works to remove these types of stains, but when we asked HiSmile to provide us the details of these studies, they didn't respond.
How do the costs compare to other tooth whitening treatments?
- The HiSmile Teeth Whitening Kit, containing three tubs of gel (which the company says is enough for six uses), an LED light, a mouth tray and a shade guide, costs $79.99. HiSmile also markets a range of other products, such as whitening pens ($29.99), toothpastes ($19.99 for two tubes) and mouthwash ($29.99).
- Whitening kits that make very similar claims about their effectiveness and contain gel, a mouth tray and light are available at the supermarket or pharmacy for half the price of HiSmile.
- Toothpastes with micro-polishing particles, which Walsh says can remove stains, cost around $5.
- Going to a dentist for teeth whitening will cost from around $400, up to $1600 for treatment for very difficult stains.
Teeth whitening tip
If you're concerned about surface stains on your teeth, visit the dentist for a clean. If you have private health insurance with extras cover, you may not have to pay a gap.