When a filing is large, roughly 50% of the tooth, the tooth is at great risk of breaking. A crown or onlay (partial crown) can be used to prevent the tooth from fracture and/or needing more invasive treatment. Crowns are also used to repair already broken teeth, to restore them to their original shape and function. They may cover only a portion of the tooth, or the entire tooth. Once cemented permanently in place crowns function and are cleaned the same as a natural tooth. Dr Beard uses the most current, metal free all-ceramic materials, providing a durable, safe and aesthetic outcome.