Professional teeth whitening in Cardiff

What it’s for

Teeth naturally darken over time, and food, drink and smoking can add staining. Whitening can lighten the colour of natural teeth. It does not change the colour of crowns, veneers, fillings or bonding.

In the UK, whitening must be prescribed by a dental professional and is only available to adults aged 18 and over, unless it is needed to treat or prevent disease.

Illustration of the same front tooth twice: before whitening, a darker, warmer natural shade, and after whitening, lighter — How whitening lightens a tooth
Before
Teeth darken naturally with age, and tea, coffee, red wine and smoking can stain them.
Whitening gel
Applied to the surface of the teeth, as prescribed by your dentist. It passes through the enamel and breaks down staining in the layer beneath.
After
The same tooth, lighter. How much lighter varies from person to person.

Who can legally whiten teeth in the UK?

In the UK, tooth whitening is classed as dentistry. It can only be provided by a registered dental professional: a dentist, or a dental hygienist or dental therapist working to a dentist’s prescription. It is illegal for anyone else, including beauty salon staff, to carry out whitening.

The law also limits the strength of whitening products. Those used in professional whitening can contain no more than 6% hydrogen peroxide, including any released from carbamide peroxide, and can only be supplied to dental professionals. They may only be used after a clinical examination, and the first application in each course must be carried out by a dental professional or under their direct supervision. Products sold directly to the public can contain no more than 0.1%.

At our practice in Pontcanna, Cardiff, whitening is prescribed and supervised by your dentist after an examination. Wherever you go, you can check that the person treating you is registered on the General Dental Council’s online register.

Your consultation

Your dentist will check your teeth and gums, look at any existing fillings or crowns that may affect the result, and talk with you about the shade you would like and what is realistic for your teeth.

They will explain exactly how the whitening is carried out, how long it takes and how to look after your teeth during treatment.

Is whitening right for you?

Whitening tends to work well on healthy natural teeth with yellowish or brownish discolouration. Your dentist may suggest waiting, or a different approach, if:

You have decay or gum disease, which should be treated first
Your teeth are very sensitive, or you have worn enamel or exposed roots
You are pregnant or breastfeeding, when it is generally advised to wait
The discolouration is grey or banded, for example from certain antibiotics taken in childhood, as this tends to respond less well

What happens

Assessment
A check that whitening is suitable and safe for you.
A realistic shade
An honest conversation about the result you can expect.
Whitening
Treatment as prescribed and supervised by your dentist.
Review
A look at the result, and advice on keeping it.

What you might notice

Any effects of professional whitening are usually mild and short-lived, and your dentist will show you exactly how to use it. You may notice:

Some sensitivity to hot or cold, which usually settles within a few days of finishing. A toothpaste for sensitive teeth can help
Slightly tender gums where the gel has touched them, which soon fades
Existing white marks on the teeth looking a little more noticeable for a while

Looking after your teeth afterwards

A few everyday habits can help your result last longer:

Your dentist may suggest avoiding strongly coloured food and drink for a day or two after whitening, while teeth pick up stains more easily
Rinse with water after tea, coffee or red wine
Brush twice a day with a fluoride toothpaste and clean between your teeth
Keep up regular hygiene visits, which remove surface staining as it builds up
If your dentist prescribes top-up whitening, use it only as directed

Alternatives to consider

Whitening isn’t the only way to change the colour of your teeth, and it isn’t always the most suitable. Depending on the cause, your dentist may suggest:

A professional clean, such as a scale and polish or an air polish, where the problem is mainly surface staining
Composite bonding or a veneer, for a single discoloured tooth or where you would also like to change a tooth’s shape
Replacing visible fillings or crowns after whitening, so that they match your new shade
Leaving your teeth as they are: whitening is a cosmetic choice, not a health need

Fees

Teeth whitening: £300

Private fee guide, September 2026. Where a fee is shown as “from”, the final cost depends on your treatment; your dentist will explain your options and their costs before any treatment begins. See all fees.

Questions

Will whitening change the colour of my fillings or crowns?

No. Whitening only affects natural teeth. If you have visible fillings, crowns or bonding, your dentist will explain how that may affect the overall result.

Is the result permanent?

No. Results fade gradually, more quickly with tea, coffee, red wine and smoking. Your dentist can advise you on how to maintain them.

Will my teeth be sensitive?

Some people notice sensitivity during whitening, which is usually temporary. Tell your dentist if it happens and they will advise you.

Is teeth whitening safe?

When it’s prescribed after an examination and used as directed, professional whitening is generally considered safe for adults. We’d steer clear of products bought online, which may be stronger than the law allows or too weak to work. Trays made for your teeth fit closely, which keeps the gel where it should be.

Do whitening toothpastes work?

They can help remove some surface staining, but they don’t change the natural colour of your teeth. Some are quite abrasive, so ask your dentist if you’re unsure which to use.

One of my teeth has gone darker. Can whitening help?

A single tooth that darkens, often after a knock or root canal treatment, is worth checking first, sometimes with an X-ray. Whitening the outside of the tooth may not help much in this case, and your dentist will explain the options.

How much does teeth whitening cost?

The current fee for teeth whitening at our practice is £300, as shown in the fee list on this page. Your dentist will explain what it includes, and whether you need any other treatment first, at your consultation.

Can I have whitening before a wedding or special occasion?

Yes, but it’s wise to plan ahead. Your teeth need to be examined first, any treatment such as fillings may be needed beforehand, and it helps to leave time for any sensitivity to settle. Your dentist can advise on timing at your consultation.