Teeth whitening: what you need to know about how to whiten your teeth
Teeth whitening is one of the most popular treatments for patients who want to improve the aesthetic of their smile, as well as their confidence.
There are numerous types of treatments for teeth whitening available, including professional whitening at the dentist or home. In this article, we explain how tooth whitening treatments work and why it's important to seek advice from an experienced professional before starting.
What is teeth whitening?
Teeth whitening is a cosmetic dentistry treatment that lightens the colour of the teeth by one or more shades, helps remove stains and gets rid of yellow teeth, improving the overall appearance of the smile.
Every patient is unique, and so is every set of teeth. Therefore, the results of teeth whitening will differ from one person to the next. Patients should have realistic expectations before undergoing tooth whitening treatment.
Even though the large majority will achieve a visibly whiter and brighter smile, sometimes, accomplishing a perfectly white shade isn’t possible. However, for most patients, teeth whitening is a great way to get rid of yellow teeth!

Why are my teeth yellow?
If you ask yourself, “Why are my teeth yellow?”, here we outline the possible causes of yellow teeth. Before understanding how whitening works, it is important to know what causes yellow teeth so that you are better equipped to keep your teeth whiter for longer after treatment.
- Natural teeth colour:
We all have a different natural shade of enamel that, in healthy teeth, ranges from yellow to white.
- Age:
Over the years, teeth tend to yellow and darken due to wear and accumulation of stains. As a result, teeth bleaching may become increasingly difficult, but not impossible, as time passes.
- Translucency:
Genetics and the shape and size of the teeth can play a role in the causes of yellow teeth. The thicker and more opaque the teeth are, the whiter they tend to be. On the other hand, thinner and more transparent teeth tend to appear more yellow and are also more difficult to whiten.
- Eating habits:
Tea, coffee, wine, and other highly pigmented foods gradually stain the teeth, turning them yellow or greyish. Additionally, acidic foods directly attack the enamel, which can cause teeth to become thinner and more yellow in appearance.
- Tobacco:
Cigarettes are not only an enemy of our general health but also of our oral health. Nicotine gradually stains and discolours the teeth.
- Trauma:
A tooth that has been damaged may appear darker than others.

How can you whiten your teeth? Find out whether teeth whitener will work for you
A common question amongst those with severe discoloration, people with certain dental health conditions, or people who have had a cosmetic dental procedure is, “How can you whiten your teeth?”. In this section, we’ll outline some of the cases where teeth whitening may not be suitable:
- Severe discoloration and staining:
When a patient has severe staining or yellow teeth, it’s likely that a teeth bleaching treatment will not work or will make little difference. It’s worth consulting an orthodontist before undergoing a teeth whitening treatment so they can advise whether it will be worth your time or whether a cosmetic treatment like dental bonding or veneers might be ideal for you.
- Teeth sensitivity:
If you suffer from very sensitive teeth, professional or at-home teeth whitening treatments can cause further sensitivity or irritation in the teeth and gums.
- Dental bonding, veneers, crowns or fillings:
If you have tooth fillings, crowns, veneers, and dental bonding, do not respond to whitening treatments. Therefore, these teeth will remain the same colour, while your natural teeth will become whiter, creating inconsistencies in the overall appearance of the teeth.
Top Tip
If you've had one of these treatments but want to achieve a whiter smile, you should consult with your dentist to see what your options are. You could whiten your natural teeth to your desired shade, but then your bonds, veneers or crowns would need to be replaced to match, which can be quite costly.
Types of teeth whitening
When it comes to achieving a whiter smile, you have a few options. Each method has its own strength; some are more effective than others, and some are more efficient. Here we will expand on each of them so you can find the best fit for you.
Professional laser teeth whitening with a dentist
Professional laser teeth whitening is one of the best ways to get whiter teeth and is often done in a single session at the dentist. Laser whitening involves applying a whitening product to your teeth and exposing them to a laser.
The laser activates the agents in the whitening gel and helps them penetrate the tooth for immediate results. However, it is important to know that the laser technique cannot achieve a brilliant white on severely stained teeth.
Cons of laser whitening
Despite the process lasting up to three years, there are questions of increased sensitivity when using this method, which can manifest as mild to moderate pain.
Teeth whitening at home
It’s possible to whiten teeth in various stages at home using teeth whitening kits or moulds prepared by your dentist. Your dental specialist will prescribe you a teeth whitening gel and explain how to use it at home and how to care for your teeth while doing so.
Depending on the colour of your enamel and the nature of your teeth, they should direct you to the product that best matches your needs.
Your dentist should also indicate the suggested length of use and how often you should repeat the teeth whitening procedure. Teeth whitening with moulds requires several sessions at home to obtain a whiter smile.
LED teeth whitening
Investing in an LED teeth whitening treatment can reduce the risk of sensitivity and still yield results in a professional and dedicated dental treatment centre.
How?
LED whitening uses light-emitting diodes (LEDs), which emit a broad-spectrum blue light to accelerate the whitening gel’s reaction. This is the preferred method at Impress to ensure the safety of our patients and minimise the risk of post-treatment sensitivity.
For the most efficient and long-lasting results, it is recommended to alternate between professional whitening and whitening with moulds at home, combining both types of teeth whitening.
Your dentist should advise you on how to proceed and on the number of sessions required to obtain your desired result.
How to get whiter teeth: how does teeth whitening work?
If you’re wondering how teeth whitening works, in this section we’ll explain what hydrogen peroxide is and what it does to get rid of yellow teeth.
Regardless of the type of treatment you choose, teeth whitening works by applying a hydrogen peroxide-based gel. This gel can be made from hydrogen peroxide itself or from carbamide peroxide, which decomposes into hydrogen peroxide.
But how does this work to get rid of yellow teeth and achieve white teeth? These substances work by being absorbed into the pores of the enamel and penetrating the inner layers, whitening the teeth from the inside.
It is important to remember that hydrogen peroxide teeth whitening or any other teeth bleaching treatment should always be carried out under the supervision of an experienced dental or healthcare professional. Your teeth should first be checked by a dentist to determine whether they are suitable for a teeth whitening treatment.

Teeth whitening cost in the UK: how much is it?
If you’re wondering how much teeth whitening is in the UK, the answer is that the cost may vary depending on your specific location, the type of treatment and equipment used.
It's important to know about the expertise and reputation of your provider and dentist. At Impress, the whitening price range depends on an individual basis, with the flexibility of 0% repayment.
Below we outline the average cost of teeth whitening in the UK according to the type of treatment:
- On average, the cost of a professional laser teeth whitening treatment tends to fall between £500 and £1,500. In some cases, this price also includes a kit to take home so that you can maintain the colour of your teeth. However, you should consult with your dentist beforehand to find out what the cost of your treatment includes.
- Professional kits for teeth whitening at home using moulds typically cost between £150 and £700.

Align and whiten your teeth at Impress
Looking for a brighter and whiter smile? You can find professional teeth whitening treatments at many of our Impress clinics, where our expert doctors can assess your case and personalise your treatment so that you can achieve the best results quickly and safely.
Furthermore, at Impress we specialise in orthodontic treatments using clear teeth aligners, so if, in addition to a whiter smile, you also want more aligned teeth, you can get in touch to find out more about our treatments.
To find out whether your nearest Impress clinic offers teeth whitening, or to find out more about our aligner treatments, you can book a complimentary consultation through our website, by phone at +44 20 3808 1072 , or via WhatsApp.
Frequently asked questions about teeth whitening
Does teeth whitening hurt?
No, when teeth whitening is carried out by a professional, it does not hurt. It is possible to experience some sensitivity during or shortly after your treatment, especially when exposed to hot or cold temperatures, or when eating acidic foods, but this should disappear after a day or two.
Does teeth whitening damage the teeth?
If performed correctly and under medical supervision, teeth whitening does not damage the teeth. If the patient does not follow the recommendations of their dental specialist and if they use the product too frequently, or for a longer time than indicated, it is possible that they may damage their teeth. For this reason, treatment should always be carried out under medical supervision.
How long does the result of teeth whitening last?
If you’re thinking about a teeth whitening treatment and you’re asking yourself “How long does the result last?”, the answer depends on a variety of factors including your lifestyle, habits, and the type of treatment used. Generally speaking, the results of teeth whitening can last between 6 months and 2 years; after which you may have to have a touch-up to maintain your results.
How often should you whiten your teeth?
How often you should whiten your teeth depends on the duration of the initial results. Depending on the patient, a touch-up should be scheduled every 6 months or even once a year.
How long does whitening teeth take?
For those wondering, “How long does teeth whitening take?”, it depends on the severity of your case and on the results you want to achieve. However, when having a teeth whitening treatment with a dentist, you should expect to schedule up to three sessions. Each session can last anywhere from 30 minutes to an hour.
What is the best way to whiten teeth?
There are many opinions on which is the best way to whiten teeth, but what is considered most effective and efficient is a professional laser teeth whitening. It is the safest method that also provides the quickest results. The only downside of professional whitening is that it can be quite costly. Therefore, we recommend combining laser treatment with a dentist with teeth whitening moulds at home for the best price and results.
What not to eat after teeth whitening?
As previously mentioned in the article, we have some recommendations on what not to eat after undergoing a teeth whitening treatment. You should stay away from dark liquids like coffee and wine, as well as liquids with high acidity like fruit juices, fizzy drinks, and alcohol. When it comes to foods, it’s best to refrain from eating anything overly sugary like cakes or ice cream, and foods with artificial coloring like ketchup and ice lollies. This is true for both teeth whitening treatment at home and professional whitening in a clinic as these foods can be harmful for any recently-whitened teeth.