Crowns are coverings that are placed around teeth to help protect them. They are placed on teeth for different reasons. 1. Teeth that have had root canal therapies become brittle and need them. 2. Teeth that have large fillings due to breakage of tooth structure need them.3. Teeth that hurt when chewing due to a hairline fracture need them. Todays materials are very good. Dr. Stevens office uses the latest materials that look natural and have good strength. He also works with a local dental lab to make the crowns fit very well.