Tooth discolouration is abnormal tooth color hue or translucency.

Teeth are an integrated part of facial aesthetics and are involved in complex social cultural and psychological interactions. Person having discoloured teeth direly require bleaching and treatments. For the proper treatment and diagnosis of stained teeth one should understand the mechanism behind discoloration and the clinical features of different types of discolorations. Here, in this article classification of severe discolorations, their causes, how the underlying mechanism behind tooth discolorations affects the outcome of a treatment, different dental treatments of different discolorations have been described.