What is teeth whitening and what are the best home kits, strips and treatments?

TEETH whitening lightens teeth and makes them appear brighter by helping to remove stains and discoloration.

IF your smile has become stained from tea and coffee, you may have considered getting your teeth whitened.

There are various routes to go down, with the most effective being the most costly - with a dentist.

At-home kits are popular, but you need to be wary of the dangers.

An investigation from consumer group Which? has found that some DIY kits sold online have dangerous levels of bleaching chemicals.

Using these products could lead to gum burns or tooth loss - far from the gleaming smile you hoped for.

The worst had more than 300 times the recommended amount of bleach.

So how can you safely chose the best option for you?

Here's what you need to know about teeth whitening:

What is teeth whitening and why do teeth become stained?

It's rare you'll come by someone with naturally bright white teeth.

Dentin, the hard, inner part of teeth, is primarily responsible for tooth colour, and this darkens as you get older, making the teeth appear yellow or grey.

The top layer of the tooth - enamel - can be stained yellow by what you eat and drink, with coffee, red wine and spices being the main culprits.

And brown teeth can be a result of a medication, injury to the tooth or nerves and smoking.

Teeth whitening lightens teeth and makes them appear brighter by helping to remove stains and discoloration.

The procedure is one of the most popular when it comes to cosmetic dentistry and most dentists perform some kind of tooth whitening.

How long it takes to reach the desired shade, and how long it lasts, will depend greatly on your method of choice.

But it isn't permanent, lasting between a few months to three years before needing topping up.

How do you whiten teeth, what are the different methods and are there any risks?

There are many products and techniques that help whiten teeth.

Teeth whitening at the dentist is the most successful because the bleaching gel contains 6 per cent hydrogen peroxide.

For comparison, over-the-counter kits are legally not allowed to contain more than 0.1 per cent hydrogen peroxide.

With a dentist, a gum shield will be moulded to your teeth. You then apply the bleaching gel to the shields and wear it on the teeth overnight, or for several hours in the day.

After roughly two to four weeks, depending on the shade desired, the teeth will be brighter.

It is not offered for free on the NHS except for medical reasons. Therefore it'll privately cost between £150 and £700 depending on the treatment offered by the dentist.

Unfortunately it is not a one-off procedure – it will need to be repeated to maintain the same level of brightness. But the fee is smaller for "top-ups".

Any dentist can whiten teeth as long as they're registered with the General Dental Council.

Having teeth whitened at a unqualified beauty salon can carry risks and they are breaking the law by using products as strong as that used by dentists.

Another popular technique, with the supervision of a professional, is laser whitening, or “power whitening”.

A bleaching product is painted onto teeth before a special light is shone on to the area to activate the product.

It takes just one hour, but is more costly - up to £1,500.

At-home methods 

Those looking to whiten their teeth can also do it from the comfort of their own home.

DIY kits come in the form of strips, gels with low concentrated bleach, or gum shields with UV lights.

At home gel kits don’t really contain enough whitening product to make a big difference – and they can be risky if not applied correctly.

Some contain generic sized mouth guards which are not properly fitted to your teeth. This can lead to the bleaching gel leaking out onto the gums, which can cause corrosion.

A study published in February 2019 found that at-home whitening kits can damage teeth, leaving them weaker and more sensitive, even when used in line with the manufacturers guidance.

It led to calls from some dental experts for them to be banned.

Other DIY methods of brightening teeth, such as charcoal powder and special toothpastes are likely to only have a negligible impact – especially if teeth are particularly stained.

Some tips and tricks go viral online but are more often than not best avoided.

Theodora Little, dental hygienist for CURAPROX UK said the trend of using bicarbonate soda is "extremely abrasive" and can damage the teeth.

Health professionals have slammed the TikTok fad of applying pure hydrogen peroxide on to the teeth with a cotton bud as “extremely dangerous”.

If you want to try an over-the-counter teeth whitening kit, it's best to ask your dentist who may be able to point you to a professionally-approved alternative.