Overview

Teeth whitening uses a bleaching product or an abrasive to make teeth whiter. Teeth whitening isn't a medical procedure—it doesn't result in healthier teeth. But it can result in a brighter smile. This in turn can make people feel better about themselves. Teeth whitening works better for some types of stains than others.

There are two types of teeth whitening.

Bleaching.

Bleaching your teeth changes the colour of the tooth enamel and removes both surface stains and those deeper in the teeth. Your dentist can bleach your teeth at their office. Or you can do it yourself with a kit your dentist gives you or with a kit you buy at a store. The chemical used to bleach teeth is generally carbamide peroxide. Different products use different concentrations of this chemical.

Whitening toothpaste.

Whitening toothpastes use a rough (abrasive) material that "scrapes" off surface stains and polishes the teeth.

Bleaching

Teeth bleaching is a type of teeth whitening. It can be done by a dentist or at home.

For in-office bleaching, the dentist often combines bleach with a laser or light to speed up the process. A visit usually takes from 30 minutes to 1 hour. You may need more than one treatment. Your dentist will protect your gums with a gel or shield and then put the bleaching agent on your teeth. The bleach concentrate used for the in-office process is generally stronger than that used in other methods. That's because the dentist can watch how it is used.

Your dentist may also give you a kit with a mouthpiece and gel containing the bleach. Your dentist may make a custom mouthpiece to fit your teeth. These kits usually use a lower concentration of bleach than an in-office process. Your dentist will tell you how often to wear the mouthpiece and for how long.

An over-the-counter kit is similar to what your dentist gives you. The bleach concentration, how you use it, and how long you use it vary between products. For example, some products use a mouthpiece. Others use strips you lay across your teeth.

All of these methods have different costs, and some methods give better results than others. Dental insurance usually won't pay for them. You choose the method that works best for you and that fits your budget.

Teeth can become sensitive when you are using the bleaching solution. But this sensitivity usually goes away when you finish your treatment. A mouthpiece that doesn't fit well may hurt your gums.

Remember that whitening isn't permanent. Your teeth will slowly become discoloured again. Some lifestyle choices, such as drinking coffee or using tobacco, will speed up how fast your teeth lose their new whiteness.

Always talk with your dentist before you use tooth whitening, especially if you have many fillings, crowns, or very dark stains.

How well whitening works

Talk to your dentist before whitening your teeth. Teeth bleaching works best on natural teeth.

Bleaching may not work if you've had bonding or have tooth-coloured fillings in your teeth. The bleach won't change the colour of these materials, so they will stand out if you whiten the rest of your teeth.

Teeth whitening in children and teens

Children and teens with discoloured teeth may have a negative self-image that can result in unhealthy behaviour. Teeth whitening may help them with their self-image.

In children and teens, stained or discoloured teeth may be caused by:

• An injury or infection.
• Fluorosis, which means using too much fluoride. This can change the colour of the teeth.
• The antibiotic tetracycline. Using this antibiotic can cause stains on the teeth.

It's important to discuss teeth whitening with your dentist. If your child still has a mix of primary and permanent teeth, whitening all teeth may result in teeth being different shades of white. That's because the thickness of the tooth enamel is different in these two types of teeth. Colours may also change when the permanent teeth replace the primary teeth.