The retreatment time also is much shorter than the original treatment time. Several studies during the past five years have proven bleaching to be safe and effective. The American Dental Association has granted its seal of approval to some tooth bleaching products. Some patients may experience slight gum irritation or tooth sensitivity, which will resolve when the treatment ends. No one can really predict how much lighter your teeth will become.
Every case is different.
Typically, there is a two-shade improvement as seen on a dentist's shade guide. The success rate depends upon the type of stain involved and your compliance. Bleaching can only provide a shift in color from gray to a lighter shade of gray, for example. Bleaching does not lighten artificial materials such as resins, silicants, or porcelains.