What causes a discoloured tooth?

Decay. Trauma. Gum recession exposing a dark root. A dead or receded nerve in the tooth. An existing root canal treatment. An old silver filling that has leeched gray color into the tooth. An old composite filling that is staining underneath the edges or has discolored over time. Tooth wear leading to the exposure of the darker layer of tooth under the enamel. Stain from food or beverages.

What can I do to minimize my risk of a discolored tooth in the future?

Consult your dentist regarding your particular situation. Some options that may be recommended are: Repair decayed teeth. Treat teeth needing root canal treatments. Address exposed tooth roots. Replace old fillings. Address bite problems. Bleach the inside of root canal treated teeth or use dental whitening products (at home or in-office).