As we get older our teeth get darker. This is partly due to our getting older, but it is also caused by the foods we eat and drink, and by other habits such as smoking. Tea, coffee, blackcurrant juice, red wine and other foods that have strong colours can have an effect on the overall colour of our teeth. Teeth may also darken as a result of some antibiotics. ‘Calculus' or tartar can also affect the colour of your teeth. Some people may have staining under the enamel surface or tiny cracks can appear in the teeth which take up stains.
To begin the tooth bleaching process, you have trays made specially to fit into your mouth like gum-shields. The whitening gel is then put in the trays and you will be given a routine to follow at home. Normally you use the trays once a day for one hour. Over a period of two weeks you begin to notice an improvement in the whiteness of your teeth. You may need to continue with the treatment for an extended period to achieve a certain level of whiteness.
Tooth whitening agent cannot whiten your crowns, bridges, veneers or
fillings (as these are not natural teeth), but it can whiten teeth
discoloured by organic stains, but not teeth stained by metal, such as
old amalgam fillings. The outcome of how your teeth lighten varies from
person to person. When the bleaching treatment is complete your teeth
stay whitened for a considerable period. If your teeth darken again you
can repeat the procedure as you can keep the trays in a safe place, so
they can be used in the future.