They're unsightly and can often be a sign of poor dental health, so here are the causes, preventive measures and treatments you can explore to keep your teeth sparkling.

If you're looking to improve your smile and dental health, read on -- the following pages provide information regarding the causes, symptoms, treatment and prevention of discoloured teeth.

There are various causes for tooth discolouration, which include both intrinsic and extrinsic factors.

Extrinsic causes of tooth discolouration:

• It occurs when the outer layer of the tooth or the enamel is stained.
• Coffee, wine, colas and other drinks/foods can cause teeth to stain.
• Smoking is also a cause for discolouration.
• Tooth decay may lead to staining.
• So do broken down fillings.

The good news is that extrinsic stains are easy to remove.

• This occurs if the inner structure of the tooth, ie dentin, is darkened or gets stained yellow. Intrinsic stains are difficult to remove and take longer too.
• Flurosis: It occurs due to excess exposure to fluoride in childhood.
• If a pregnant mother used tetracyclines (antibiotics) during pregnancy, they cause discolouration in the teeth of the baby born.
• If tetracyclines are used by children less than eight years of age.
• Trauma can also cause discolouration.
• High fever as a result of childhood infections results in white spots on the teeth due to poor calcification.
• Dentinogenesis imperfecta: It is a condition in which children are born with gray, amber or purple discolourations.
• Loss of nerves or blood supply to the tooth.
• Porphyrias: The teeth are discoloured brownish-red.
• Erythroblastosis fetalis: The teeth are discoloured brownish-blue.

• Staining on the enamel of a tooth.
• White streaks, yellow tints, brown spots and pits on the enamel.
• Yellowish discolouration on the dentin.

If you suffer from discoloured teeth, you can opt for:

• Brush your teeth after every meal.
• Floss daily.
• Avoid drinking colas, avoid smoking.
• Avoid eating paan.
• Rinse your mouth after consuming coffee, tea, colas and wine.