The two substances that are the cause of these stains are tar and nicotine.
The surface of the teeth turn a yellow brown colour when these two substances creep into the tiniest openings in the tooth enamel.
Although nicotine is colourless it turns yellow as soon as it is mixed with oxygen.
Tar and nicotine will settle in the mouth through the inhalation of tobacco.
Tobacco stains can be removed because they are located on the outside of the teeth.
The first move towards having stain free teeth is to either quit the habit or never begin.
Good oral hygiene consists of brushing at least twice a day. Flossing and using antiseptic mouthwash are not able to completely protect your teeth from stains, but will help. You should at least rinse your mouth after smoking tobacco if you cannot brush each time.