Where the ‘nerve’ of a tooth has died (through damage or disease) and the tooths root have been filled, bleach is put inside the tooth, under a removable tray or temporary dressing. This can take from a few days a week. There are two ways or bleaching the outside of the teeth. One takes place at home and the other in the dentist’s surgery.

Home bleaching works like this:

• The dentist will give you weak bleach jelly to use at home in a tray which fits closely round your teeth. The tray makes sure that the jelly does not burn your gums. You will need to put the tray in your mouth overnight (for a few hours) on several occasions, as instructed by your dentist (probably over a period of weeks).
• The dentist will need to use a putty-like material to make moulds of your mouth (called ‘impressions’), so a dental technician can make the tray to fit. At your next appointment, your dentist will check that the tray fits and show you now to put the bleach in the tray at home.

Bleaching in the surgery works like this:

• Your dentist (or dental care professional) will use a stronger bleach jelly than is used for home bleaching. Dentists use this method to bleach all the teeth at the same time in either your upper or lower jaw. The strong bleach will touch the teeth for less time than with home bleaching.
• The dentist should protect your gums. They will paint the bleach onto the teeth and either shine a special light at them or just leave the bleach on the teeth for some time.
• The bleach is then washed off with water.

For both techniques, your dentist will make a note of your tooth colour using model teeth in different shades before they treat you.

Occasionally bleaching can cause your teeth to become more sensitive to hot, cold and sweet things. Should this occur, stop bleaching for a night or two if you are using the night guard bleach, and use desensitising toothpaste. If the problems persist, see your dentist.