Stains on the surface or changes in the tooth material can make your teeth to become discoloured. Tooth discoloration is divided into three main categories by dentists:
Extrinsic Discoloration: It occurs when the enamel (outer layer of the tooth) is stained by coffee, wine, cola or other drinks or foods. Smoking is a major reason behind extrinsic stains.
Intrinsic Discoloration: When the inner structure of the tooth (the dentin) darkens or gets a yellow tint, it is known as intrinsic discolouration. It can be caused due to excessive exposure to fluoride during early childhood, the maternal use of tetracycline antibiotics during the second half of pregnancy and the use of tetracycline antibiotics in children 8 years old or younger.
Age-related Discoloration: It is a combination of extrinsic and intrinsic discolouration characteristics. In addition to stains caused by foods or smoking, the dentin naturally turns yellow over time. The enamel covering the teeth gets thinner with age, and allows the dentin to show through. Chips or other injuries to a tooth can also cause discoloration, especially when the pulp has been damaged.
Rare conditions like dentinogenesis imperfecta can cause babies to be born with gray, amber or purple discolorations.
Dentists can remove some tooth discoloration with professional cleaning, such as stains caused by coffee. However, a lot of stains are permanent. A bleaching gel can be used to whiten teeth. In some cases, if the discoloration is severe, a crown or veneer may be required to cover it.
Brushing your teeth after every meal will help to prevent some stains. Dentists recommend that you rinse your mouth with water after having wine, coffee or other drinks or foods that can stain your teeth. Regular cleanings by a dental hygienist also will help to prevent surface stains.
Read more articles on Understanding Tooth Discolouration.