Crowns are a cosmetic restoration used to strengthen a tooth or improve its shape. Crowns are most often used for teeth that are broken, worn, or partially destroyed by tooth decay.
Crowns are "cemented" onto an existing tooth and fully cover the portion of your tooth above the gum line. In effect, the crown becomes your tooth's new outer surface. Crowns can be made of porcelain, metal, or both. Porcelain crowns are most often preferred because they mimic the translucency of natural teeth and are very strong.
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 then sculpted just for you so that your bite and jaw movements function normally once the crown is placed.
A bridge may be used to replace missing teeth, help maintain the shape of your face, and alleviate stress on your bite.
A bridge replaces missing teeth with artificial teeth, looks great, and literally bridges the gap where one or more teeth may have been. Your bridge can be made from gold, alloys, porcelain, or a combination of these materials, and is bonded onto surrounding teeth for support.
The success of any bridge depends on its foundation — the other teeth, gums, or bone to which it is attached. Therefore, it's very important to keep your existing teeth, gums, and jaw healthy and strong.