The lightening of the color of the tooth through application of a chemical agent, which tends to decolorize the pigmentation present on the tooth, is referred to as bleaching.
Bleaching technique may be classified as to whether they involve a living tooth or a tooth with no blood and nerve supply. The procedure can be carried out within the dental clinic or by the patient at his residence.
Bleaching generally has an approximate life span of 1 - 3 years, although this change may be permanent in some situations.