Respuesta :
The teeth and the skin tend to be stained by the action of nicotine and tar. Nicotine is a substance that is extracted from the leaves of tobacco and that can also be produced synthetically; It is a toxic drug that in small doses produces euphoria, decreased appetite, etc., and in high doses can cause serious poisoning.
Nicotine and Tar are the two major components of tobacco that causes teeth staining. Just like our skin, our teeth have pores, which can easily absorb nicotine and tar and turn white teeth yellow. Although nicotine itself is colorless but when it combines with oxygen it turns yellow. Even nicotine infuses electronic cigarettes causes teeth discoloration.
Most people have dark brown stains on their teeth, it is because of the way they consume tobacco. When tobacco is chewed along with saliva, it produces dark brown liquid which is extremely staining.