Functional purpose: When a tooth is heavily filled, the remaining structure undergoes a lot of stress. This could result in the tooth cracking and in due time if the crack is not diagnosed, it could lead to fracture. At this point, the tooth may have to be extracted.
The whole idea of crowning is to protect the “stressed” tooth from fracture. Crowning is also necessary for teeth that have been root canal treated. This is because a root filled tooth becomes weak and brittle.
Aesthetic purpose: This is to change the appearance of your teeth as part of cosmetic dentistry. You may have some forms of discoloration, ,malformation of teeth and dental enamel defects which may require you to crown your teeth if you want to have a better smile.