Thanks to our penchant for delicious yet staining delights such as coffee, red wine and cigarettes, many of us long for whiter teeth.
Going to the dentist for professional whitening is expensive, so it’s no surprise that cash-strapped individuals turn to cheaper, home whitening options.
You only have to open Instagram to find yourself bombarded with ads for at-home devices that claim to take your gnashers from drab to fab.
However, do these kits work, or are we being duped with heavily edited ‘before’ and ‘afters’ and utterly useless products?
How does teeth whitening work?
Teeth are made up of an inner dentin layer and a harder outer enamel layer. Enamel is mostly translucent, so despite it being on the outside, it’s largely dentin that determines the colour of your teeth.
Teeth whitening products generally whiten teeth using one of two active ingredients – hydrogen peroxide or carbamide peroxide – which penetrate the porous enamel and lighten the colour of the dentin by breaking down the stains. This explains why toothpaste alone can’t get rid of those stubborn coffee stains.
Hydrogen peroxide is the more aggressive of the whitening agents, while carbamide peroxide is the more chill option, slowly breaking down into hydrogen peroxide and urea, making it a better choice for those with sensitive teeth.
These days, most home kits contain either strips impregnated with whitening solution or dental trays that you fill with whitening gel.
Getting your teeth whitened at the dentist will either involve having your teeth whitened in the dentist’s chair in one appointment, or taking home a set of custom fit trays and teeth whitening gel to do it yourself over the course of a couple of weeks.
Heads up – it’s a good idea to get your teeth professionally cleaned before doing any whitening treatment as plaque and tartar can create a barrier between your teeth and the whitening agent.
Teeth whitening will not work on dentures, crowns, fillings or veneers.
Is home whitening as good as dentist whitening?
Put bluntly, in the UK – no.
EU regulations ensure that over the counter teeth whitening kits sold in the UK can only contain up to 0.1% hydrogen peroxide, while dentist-supplied kits can contain up to 6%.
Can home kits at this strength work?
‘They will likely help remove just the surface staining that collects on our teeth,’ dentist Dr Guy Barwell, co-founder of The Implant Centre, Hove tells Metro.co.uk.
‘The peroxide level is so low that it is unlikely to remove any of the intrinsic tooth discolouration, so some users will be disappointed, depending on precisely why the teeth are unsightly.’
The strongest strips you can buy in the UK are in the Spotlight Oral Care teeth whitening system (£40 for 14 treatments), which contain the maximum allowed level of hydrogen peroxide. They’re also the only whitening strips sold in the EU that contain hydrogen peroxide.
Spotlight whitening strips were developed by Irish dentists to ‘safely and effectively whiten your teeth with minimal tooth sensitivity’ and their newer kits contain toothpaste tubes that are 100% recyclable, which is a bonus considering the world is burning.
‘We use a super seal technology so when you place the strip on your teeth it goes on very tightly, so the active ingredient is right next to the enamel which increases the efficacy of our strips,’ explains co-founder Dr Lisa Creaven to Metro.co.uk
You have to wear the strips for an hour once a day, which as I found out when I tested them, is quite an investment of time.
I used the strips in conjunction with their whitening toothpaste and while I noticed my teeth did get a shade lighter after about a week, I wouldn’t say the difference was worth dribbling for an hour every night for 14 days, especially as my teeth since appear to have gone back to their regular colour.
However, I didn’t experience any sensitivity whatsoever compared to stronger strips obtained from the US (more on those later), where I was subjected to what can only be described as excruciating pain.
Do products that don’t contain hydrogen peroxide/carbamide peroxide work?
My Instagram feed is flooded with pics of influencers showing off their Ross Gellar-esque teeth, peddling whitening kits that don’t contain any peroxide at all
One such kit is Hi Smile which claims to lighten your teeth by up to eight shades in just six 10 minute treatments, and has been promoted by the likes of Kylie Jenner and Conor McGregor.
The Hi Smile kit costs $59.99 (£46) and contains a teeth tray with LED light and six applications of whitening gel.
The gel contains phthalimidoperoxycaproic acid (PAP) which is an ‘active bleaching agent that whitens the discoloured molecules inside your tooth’, potassium nitrate to desensitive nerves in the teeth, and sodium chlorite for stain removal and prevention.
Can these ingredients work to lighten your tooth colour?
‘They may lighten any stains that are on the surface of the tooth, in the same way whitening toothpastes will remove or lighten some of these stains,’ Dr Barwell tells Metro.co.uk.
‘There are some concerns in recent scientific literature that the sodium chlorite in these substances may cause harm to the enamel, and this component is not currently illegal to have in whitening products.’
There are also questions raised about the effectiveness of LED lights in home whitening kits.
‘The LED light will be as effective as Buzz Lightyear’s laser was,’ says Dr Barwell.
‘Just a toy with nothing in the product that this tiny amount of light will have any effect on. May be fun, but little else.’
While UV light is used to speed things up during professional whitening treatments – this is regulated and can only be used by dentists.
Earlier this year, the Advertising Standards Authority ruled that Hi Smile were running misleading sponsored ads on social media.
By using the phrase ‘White teeth in 10 minutes’, they said that Hi Smile was misleading consumers into thinking their product could dramatically alter the colour of teeth in just 10 minutes (which is unrealistic even for a professional treatment done at a dentist).
At time of publishing this article, Hi Smile is still running these ads.
Dr Grant McGrath from Method Dental has previously criticised Hi Smile for having a one size fits all tray. Professional whitening systems give you a custom fit tray to ensure the whitening gel is held precisely aganst your teeth.
He also questioned the concentration and combination of ingredients, as well as the kit’s shade guide which shows bizarrely red shades of teeth and is nothing like the dental industry’s shade guide.
Dr McGrath used the Hi Smile kit himself and saw no change in the colour of his teeth.
If you do achieve your desired result, Hi Smile recommends you use the system once every two weeks to maintain your results. At $23.99 (£18.60) per set of gel refills, that’s quite the financial investment.
Activated charcoal powder toothpastes became popular on social media in recent years but again, any whitening effect will be superficial, removing only surface stains and not actually changing the colour of your teeth.
In fact, dentists have previously warned against using charcoal whitening toothpaste as it can be too abrasive and actually erode your enamel away.
It’s important to know that influencers promoting whitening kits may already have naturally white or professionally whitened teeth – that have nothing to do with the product they’re endorsing.
They could also have used different lighting in ‘before’ and ‘after’ photos to make teeth appear a different colour, or they may have edited their photos to alter the whiteness of their teeth. (This is actually illegal, unsurprisingly.)
Be aware of celebs with veneers who promote whitening kits, as veneers cannot be whitened.
Should I buy stronger over the counter whitening treatments from the US?
Professional treatments in the US generally use from 15-35% hydrogen peroxide, while the over the counter whitening strips sold there are also much stronger than the ones sold in the UK.
Because of this, many people – including myself – have obtained strips from the US, such as the popular Crest Whitestrips, either when travelling to America, or via potentially dodgy UK resale sites.
While you’re definitely more likely to get the whitening results you desire from these strips, you’re also at risk of unwanted side effects.
‘These can be very harmful to the enamel of the teeth, causing loss of the protective surface and allowing for decay,’ explains Dr Barwell.
‘The peroxides at high levels can burn the gums and cause all sorts of hypersensitivity reactions – most of us would not consider putting this level of bleach on other parts of our body, the mouth is surely no different!
‘Patients also seek this treatment without having had a dental check to see if they have other issues. Imagine a patient with decay on a tooth, then filling the cavity with strong hydrogen peroxide – the outcome could be fairly catastrophic.’
I’ve personally used Crest Whitestrips after a pal recommended them – her teeth are so white that Simon Cowell once complimented them, so I trusted her judgement.
However, while I ended up with sparkly white gnashers, I was also left with agonising tooth sensitivity which lasted long after I took the strips off. Go figure, with levels of hydrogen peroxide that high.
If you buy Crest Whitestrips in the UK from a dodgy website, you also run the risk of receiving a counterfeit product which could further damage your teeth.
Home teeth whitening kits in the UK can work to an extent, but generally only if you have naturally whiter teeth and are looking to remove superficial stains gained from chugging coffee and red wine.
As with most things in life, if a whitening product seems too good to be true, it probably is.
If you’re looking for dramatic, long-lasting results that don’t destroy your teeth, sadly it looks like your best option is to shell out for professional whitening at your dentist.
Better start saving, eh?
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