Tooth_bleaching

Tooth bleaching can often be accomplished on natural teeth. Discolouration of the teeth
can occur during formation of the teeth due to the taking of tetracycline during the ages
of 3 to 12, too much fluoride in the food or water during the same ages, or congenital
factors. Teeth also naturally turn darker as we age. Bleaching works best when the
discolouration is uniform on the teeth (all the teeth are equally affected and the
discolation is not blotchy or in bands). Teeth that are not amenable to bleaching can be
lightened with veneers if the teeth are otherwise in good condition. Since crowns cannot
be lightened, it is inadvisable to bleach teeth adjacent to crowns that match the
discoloured teeth since they will appear dark next to the bleached teeth.
At-Home Bleaching

The procedure for bleaching the teeth at home still starts in the dentist's office. The
dentist must make a carrier for the bleach called a "tray". This tray is a clear plastic made
from a plaster cast of the teeth. It fits over the teeth with a measured space between the
tray and the tooth surface to be bleached. Trays made using "do-it-yourself" kits are
inferior because they cannot have this controlled space and the bleaching is less uniform
or effective. Poor fit of the tray also can cause irritation of the gums
Procedure
1. Your dentist will prescribe the treatment regime; usually the tray is worn 1 - 1.5 hours
a day.
2. Thoroughly brush your teeth.
3. Remove cap from syringe tip; express a pea size quantity evenly into deepest portions
of the tray. If front teeth only need bleaching then place the gel only in this part of the
tray. You will be able to get more applications this way. If you need more gel they are
$20.00 per cartridge. Seat the tray completely and firmly onto your teeth.
4. Gently wipe off excess gel with toothbrush or clean finger,
5. When tray is removed, clean it with cool water and place in case. Brush and rinse
remaining gel from teeth. Remove tray prior to eating. Don't smoke or drink volumes of
liquid with bleaching gel in place.
After the tray is placed in the mouth it is worn 1 - 1.5 hours. Wearing the tray longer than
this does not increase the effectiveness of the treatment. Sometimes teeth may become
sensitive to cold and hot during the procedure. If this occurs use anti-sensitive toothpaste
and use the bleach only every second day.
Change will gradually occur over a period of one to two weeks The speed of bleaching
and uniformity of the result varies widely among patients. Once the desired whiteness is
achieved, the tray with the bleaching material should continue to be used periodically to
maintain the desired effect. Failure to do this usually results in the teeth gradually getting
darker again.
In-Office Bleaching

If one or more teeth needs to be bleached to match the others, for faster results, more difficult to bleach teeth or more lasting result, in-office bleaching can be done.

Source: http://meridiandental.com.au/wp-content/uploads/tooth_bleaching.pdf