Tooth whitening is a safe, non invasive way of improving the appearance of your teeth. It can be used to brighten the smile of all your teeth or to lighten the colour of a dead tooth. Tooth whitening has been in use for more than 30 years and has been proven to be safe and effective. At Hazelwood Dental Practice we use the custom tray home whitening system, which is the gold standard.


What is tooth whitening?

Tooth whitening is a way to improve the colour of your teeth using hydrogen peroxide (a type of bleach). It is safe and effective if carried out by a dentist or under the supervision of a dentist.

Tooth whitening does not remove any of the surface of the teeth or add anything to the teeth.

Is tooth whitening the same as polishing?

No. Routine polishing removes surface stains caused by coffee, cigarettes, red wine, and so on. It uses strong polishing or special pastes or gels. It can be done by:

  • your dentist or dental hygienist; or
  • you, using toothpastes, mouthwashes or gels,

which you can buy in your local pharmacy.

Routine polishing may remove surface stains from your teeth but it does not change the colour of your teeth. If you have deep stains on your teeth which don’t go away with routine cleaning and polishing, talk to your dentist. It could be tooth decay or another problem. Your dentist can advise you about the best and safest ways to fix the problem.

Tooth whitening removes both surface and internal stains using hydrogen peroxide, which is a type of bleach.

Is tooth whitening safe?

Tooth whitening carried out by a dentist (for the first visit) and under a dentist’s supervision (for the rest of the treatment) is perfectly safe. The dentist will:

  • examine your teeth thoroughly;
  • check your oral health history; and
  • decide with you whether tooth whitening is right for you.

As with any dental or medical treatment, tooth whitening must be tailored to your needs. There is no ‘one size fits all’. Tell your dentist what you want the tooth whitening to achieve and any concerns you may have. Your dentist will guide you towards the right treatment for you.

It may be that routine professional cleaning by your dentist, together with regular brushing and flossing by you, will give you the ‘stain-free’ natural smile that you’re looking for. You may not need tooth whitening at all.

Is tooth whitening successful?

In most cases, yes. However, tooth whitening treatments work differently depending on the shade of your teeth at the start of treatment. Also, the treatment doesn’t suit everyone and may not work for some people. If your teeth are likely to be difficult to treat, your dentist will tell you beforehand. Your dentist is trained to:

  • estimate the improvement in colour that you will achieve;
  • choose the right treatment plan for you; and
  • tell you how long the treatment should last.
When might tooth whitening not be successful?

Tooth whitening treatments may not work well on:

  • teeth with exposed roots;
  • teeth with ‘white’ fillings;
  • teeth with crowns or veneers;
  • teeth that have had root treatments; and
  • teeth that are not healthy.

This is why it is important to talk with your dentist when you are considering tooth whitening.

What happens during tooth whitening treatment?
  • Your dentist will apply a low but highly effective concentration of hydrogen peroxide (bleach) to your teeth using specially-made top and bottom trays that fit snugly around your teeth. Each tray is left in your mouth for a time.
  • In addition, your dentist will show you how to fit the trays correctly at home, and give you some hydrogen peroxide gel (usually in tubes) to bring home to use in the trays. You will put the trays in your mouth at home daily for the time your dentist advises. Often this will be overnight.
How long does the treatment last?

Most people will use the trays for at least two weeks but this varies from patient to patient. Tooth whitening treatment is a gradual process. It could take a number of weeks to achieve the result you want.

Are there any side effects to tooth whitening?

Tooth whitening prescribed and supervised by your dentist does not harm your teeth or general health.
The most common side effects are:

    • increased sensitivity of your teeth to hot and cold things;


  • sometimes, irritation inside the mouth.

These side effects usually disappear a few days after stopping treatment but can sometimes last for up to a month. Your dentist can help you to deal with any side effects.

How long does the whitening effect last?

The effect lasts for up to two years. Your dentist may recommend a ‘top-up’ treatment every 18-24 months to restore any slight loss of colour.

How safe and effective are tooth whitening products sold in shops and online?

It is often not clear exactly what these products contain so it’s very hard to know if they are safe to use, or even if they are effective.

Many products bought online do not clearly state their active ingredients and often contain ingredients that are banned in the European Union (EU) on safety grounds.

Are any tooth whitening products banned in Ireland?

All tooth whitening products containing more than 6% hydrogen peroxide are banned as they are not considered safe for patients.

Some so-called ‘non-peroxide’ bleaching products, such as sodium perborate and boric acid, are banned as they damage DNA (the biological information carried in your genes), reduce fertility and harm the unborn.

Always check with your dentist about any product used to whiten your teeth.

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Contact Details

Hazelwood Dental Practice,
Hazelwood Centre,

Tel: 021 4866583
Fax: 021 4866583

Opening Hours

Mon: 8.00am - 7.30pm
Tues: 8.00am -7.30pm
Wed & Thu: 8.00am - 6pm
Fri: 8.00am -6pm
Sat: By appointment only
Sun: Closed

Our early mornings from 8am and late evenings to 7.30pm are by appointment only. This is to accommodate our patients with busy schedules.