Alex Casey goes in search of the tooth, the whole tooth, and nothing but the tooth. 

If you’ve been anywhere near Instagram this year, you are probably familiar with this image. An influencer – perhaps a woman with a messy bun and a no-makeup makeup look, or a bronzed man with a six pack lounging shirtless on his bed – proudly attempting to swallow what appears to be a miniature UFO. Glowing an ethereal blue or white, these futuristic teeth-whitening gizmos appear to be a key stepping stone on the Instagram journey to getting Huge White Teeth. 

But what actually are those gadgets, available with my discount code LXKC20 if you swipe up now #spon? I called Dr Usha Narshai, teeth whitening expert from the New Zealand Dental Association, to find out the tooth. 

Are you able to explain to me how these gizmos work?

In New Zealand, the highest concentration of hydrogen peroxide in whitening products available over the counter is 6%. You’ll find that across everything – toothpastes, mouth rinses, gels, varnishes. These at-home kits are just another form of that, you get the gel and inject it into pre-fabricated trays before putting it in your mouth and turning the light on. 

What is most significant is that this process dehydrates your teeth, which is what actually does the bulk of the whitening. If you were to leave your mouth open for half an hour without any product on it, you’ll find your teeth will still whiten by about 3-4 shades. And then your regular colour will come back about 24 to 36 hours later. 

How does dehydrating your teeth make them whiter? 

Whats happens is that your tooth has an outer layer of enamel and a deeper layer of dentin. When moisture is drawn from there, it acts the same as anything with water in it does when it dries out. It’s like how an apple turns a paler shade when it is dehydrated, and then when it is rehydrated it returns to its original shade.

The anatomy of the tooth allows moisture to be drawn out and, when you dry the tooth, you will get whiter teeth. With the added peroxide product, the chemical breaks down the molecule of the stains on your teeth. Your stain won’t be as bright as a result and your teeth will appear whiter once your 30 minutes is up. 

So beyond the dehydration thing, the gel still does something, right? 

Absolutely. The gel will do something eventually but it will be no more effective than a toothpaste or mouthwash with that same level of peroxide in it. I wouldn’t say you can claim 6-8 shades lighter like some brands do, though. You might be able to for the first 24 hours, but I’d say most people want their teeth staying whiter for longer than that.

For real, long-lasting results with a product like this, I’d say you’d want to use it consistently and very frequently for 6-12 months. And it could get very annoying doing it that often. If you want something more concentrated that will get faster results, you have to do that with a dental professional. 

What about the LED light? Does that actually do anything? 

The light makes the user feel like the product is being “activated”. It’s possible it might warm up and therefore speed up the process, but there’s no research provided that suggests it makes any difference in the at-home kits. What I think the light mostly does is make sure your mouth stays open. You could put the tray in without the light, but then you haven’t got that wow factor to take a photo of. Because this is all about marketing, and the marketing is great. 

What else should people know about these at-home kits? 

It’s important to avoid black tea or coffee or red wine for about two weeks while you are whitening your teeth. Because what you are doing is changing the chemistry of the actual tooth structure which makes it more prone to staining in the aftermath. You actually become more vulnerable to discolouration, which I’d imagine is exactly what people are trying to avoid. I just really wish they came with a disclaimer to consult with a professional first. 

Have you seen an uptake in people wanting to whiten their teeth since the Instagram era started? 

Definitely. In the current climate of selfies, filters and reality TV stars, there is huge a pressure to look good. Something like this product might give you a little bit of a boost, an instant hit of confidence. This is a product that has great marketing, great packaging, but you just need to question the long-term effectiveness of it. It’s easy, it’s not harmful, it’s convenient and FDA approved, but you should always seek proper advice.

Put even more simply, there is a litmus test I always like to use with things like this. Forget the influencers – how many dentists are actually using these? How many are recommending it to their patients? I’m not going to tell anyone not to get it, I just think people probably need to do their research to make an informed decision before they buy any product through Instagram.