All the teeth that have had root canal treatments done should be covered with crowns to prevent their breakage as they have lost their natural hydrating mechanism and tend to be brittle.
Teeth that have been restored more than half by filling material should be crowned.
Tooth with bad aesthetics can be reshaped with crown to improve the aesthetics.
Damage to the tooth structure because of wear and tear can be restored with crown.
Fractured tooth can be restored with crown.
Teeth with wide spaces between them resulting in food lodgment or unpleasant appearance can be crowned.