A dental crown is recommended when a tooth is too damaged or decayed to be restored with a filling. Crowns preserve as much of the natural tooth as possible and restore its function and appearance. They are custom-made caps that cover the entire tooth, restoring it to its original shape and size. Dental crowns can be made of materials like porcelain, gold, or porcelain fused to metal. If your tooth is weak, fractured, or has undergone root canal treatment, a crown can protect and strengthen it.