Your teeth can become discoloured by stains on the surface or by changes inside the tooth. There are three main types of tooth discoloration:​

• Extrinsic– This occurs when the outer layer of the tooth (the enamel) is stained. Tea, Coffee, wine, other drinks or foods can Stained Teeth. Smoking also causes extrinsic stains.​

• Intrinsic– This is when the inner structure of the tooth (the dentine) darkens or gets a yellow tint. You can get this type of discoloration due to:
  • ​Exposure to excessive fluoride during early childhood.
  • Use of Tetracycline antibiotics during the second half of pregnancy.
  • Use of tetracycline antibiotics under 8 years old of age.
  • Trauma that affected a tooth when you were a young child. A fall, for example, may damage the developing permanent tooth or internal bleeding discolors teeth
  • Born with a rare condition called amelogenesis or dentinogenesis imperfecta. This causes gray, amber or purple discolorations.

• Age-related – This is a combination of extrinsic and intrinsic factors. Dentin naturally yellows over time. The enamel that covers the teeth gets thinner with age, which allows the dentin to show through.