What is teeth whitening?

Teeth whitening involves bleaching your teeth to lighten the colour of the enamel.

The main ingredients used in tooth whitening products are the chemicals hydrogen peroxide or carbamide peroxide. The chemicals usually come in a gel, which is applied to your teeth. Sometimes a light is used too.

What causes discoloured teeth?

The outside of your teeth can be stained when you:

• drink tea, coffee or red wine
• eat food such as spices, berries or beetroot
• smoke cigarettes

The white enamel layer on the outside of your teeth can also wear away as you get older. This exposes the dentine layer underneath. This is a yellowish colour and causes your tooth to look yellower.

Teeth can also be discoloured if:

• they are damaged or injured
• you took certain medicines, such as the antibiotics tetracycline or doxycycline, as a young child when your teeth were being formed

When might I need teeth whitening?

If your teeth are stained or discoloured, you might want to whiten them.

If you are considering teeth whitening, you should consult your dental practitioner to see if your teeth are suitable.

Teeth whitening is not recommended if you:

• are pregnant or breastfeeding
• have sensitive teeth
• have gum disease
• have cracks or holes in your teeth
• have untreated dental problems

Teeth whitening treatments will not work on teeth with crowns, veneers or fillings.

If the problem causing the yellowing is deep inside your teeth, then a whitening gel applied to the outside of your teeth won’t make your teeth whiter.

Where can I get my teeth whitened?

Only registered dental practitioners can use the strong whitening gels and products containing more than 6% hydrogen peroxide. These are most effective.

The Australian Dental Association advises that only registered dental practitioners have the training and knowledge to assess if bleaching is appropriate and safe for you. They are responsible for meeting safety and quality regulations.

Teeth whitening services may be offered by unregulated, unqualified practitioners, for example in:

• beauty and hair salons
• shopping malls
• salons
• via mobile services

You can also buy teeth whitening kits online or at the supermarket. These may contain bleaching chemicals or charcoal or bicarbonate of soda. Some kits may not be reliable and using them incorrectly can cause further dental problems.

Teeth whitening by a non-qualified dental practitioner can damage your teeth and gums. Dental practitioners are responsible for meeting safety and quality regulations and can provide a professional assessment of your teeth.

What type of teeth whitening procedure could I have?

Your dentist or dental practitioner can provide ‘in-chair’ or ‘at-home’ teeth whitening treatments.

In-chair teeth whitening

Some whitening treatments can be done while you are sitting in the dental chair.

Your dentist or dental practitioner applies strong hydrogen peroxide gel. Often a light is placed over the teeth. You should leave your dental appointment with whiter teeth.

Take-home teeth whitening

With take-home teeth whitening, your dentist or dental practitioner will custom-make thin, plastic trays that fit over your teeth. They also give you some gel in the correct strength to suit your needs.

At home, you place the teeth whitening gel in the trays. Your dentist or dental practitioner will tell you how much whitening gel to use each time and how long to wear the trays for.

This method of teeth whitening takes longer to achieve results than in-chair treatment. This doesn’t mean that the final result is better or worse.

Internal bleaching

Sometimes a dentist or dental practitioner can use tooth whitening treatment on the inside of the tooth. For example, when teeth have been injured and you have had root canal treatment that has caused staining from inside the tooth.

The whitening treatment is placed in the centre of the tooth, where the dental nerve used to be. It is left for several days before being cleaned out and fixed with a filling.

What are the benefits and risks of teeth whitening?

Teeth whitening can improve the appearance of discoloured teeth. It‘s likely to cost less than procedures like crowns or veneers.

If you have any cracks in your teeth, the bleach could cause pain or further damage.

Side effects are most likely to happen immediately after treatment. The most common side-effects include:

• temporary tooth sensitivity
• irritation of the gums or mouth

Swallowing the whitening gel can cause nausea and stomach irritation.

If the tooth whitening product contains a lot of bleaching agent, it can cause severe irritation or burns. It is dangerous to swallow the product.

Tooth whitening products containing high levels of bleaching agents must be used under the supervision of a dentist or dental practitioner.

How much does teeth whitening cost?

The cost of dental treatments and procedures depends on many factors. Always ask how much a treatment will cost before you start the treatment.

You should consider the safety of a treatment and how well it works, not just the cost.

What are the alternatives to having my teeth whitened?

Try these tips to avoid teeth staining:

• brush with a soft toothbrush and floss your teeth every day
• don’t smoke cigarettes
• rinse your mouth with water after having food or drink that can discolour your teeth

Some alternatives to teeth whitening treatment are:

• having your teeth cleaned by your dentist or dental practitioner
• using whitening toothpaste
• asking your dentist or dental practitioner about dental treatment to fix your teeth, such as veneers or crowns

Tooth whitening toothpaste

Whitening toothpastes can reduce stains on the outside surface of the tooth. The toothpastes contain special abrasives and/or whitening agents.

Some ingredients are:

• sodium hexametaphosphate
• hydrogen peroxide
• phthalimidoperoxycaproic acid — sometimes called PAP

It’s best to use a soft toothbrushes with these toothpastes, to avoid damaging your tooth enamel.  

Resources and support

Find out more about how to care for your teeth at teeth.org.au.

You can also call the healthdirect helpline on 1800 022 222 (known as NURSE-ON-CALL in Victoria). A registered nurse is available to speak with 24 hours a day, 7 days a week.