Our smile is, on many occasions, our first impression. Therefore, we are more and more concerned about having white teeth.
Teeth lose their natural whiteness due to the effects of a series of agents on their constituent parts, leading to staining or darkening.
This happens when certain agents (particularly some foods, coffee, tea, wine, tobacco, etc.) are retained and absorbed by the surface of the teeth, and also when plaque and tartar facilitate the retention and adsorption of said agents.
Staining can be associated with other kinds of dental damage that affect the gums or teeth (caries or sensitivity).