Teeth that are broken or otherwise damaged may require a crown as an overlay to aid in appearance and durability. Some cracked teeth are too weak to hold a filling, but do not need to be fully removed and may suffice with a crown placed on top of them. You can think of a crown as the artificial outer layer of a damaged tooth. The material used to make crowns can be metal, porcelain or a mix of the two. However, most people opt for a porcelain crown as they are closer in appearance to a natural tooth and can help to maintain a nice smile.
An overlay, or partial crown, may also be recommend for teeth that are not durable on their own. Crowns are created by taking an impression of your current teeth in order to make the best fit for you. This impression is then sent to a lab to create the crown, so it may sit nicely on your tooth. Using impressions allows for your crown to be custom made for your bite and your jaw to prevent any future potential for damage.
Crowns or onlays (partial crowns) are needed when there is insufficient tooth strength remaining to hold a filling. Unlike fillings which apply the restorative material directly into your mouth, a crown is fabricated away from your mouth. Your crown is created in a lab from your unique tooth impression which allows a dental laboratory technician to examine all aspects of your bite and jaw movements. Your crown is then sculpted just for you so that your bite and jaw movements function normally once the crown is placed.