Dental crowns are suggested by your dentist when there is a requirement to hold broken tooth together. A dental crown is a cap or cover that encircles the tooth or dental implant. They are used as protective coverings for your tooth. The main purpose of using dental crowns is to support and improve the decayed, damaged or deformed teeth. Dental crown are generally of three types including metal, ceramic and porcelain-fused-to-metal crowns.
Metal Crowns
Gold is most popularly used type of metal crowns. In addition, Nickel, Chromium, and Palladium are also used. These are mostly used for protecting 
and restoring damaged molars. At cases where there is requirement of great strength instead of cosmetic appearance, metal crowns are used. The durability of these crowns is much higher.
Ceramic Crowns
These are made of porcelain and function like natural teeth. These are mostly used for cosmetic purposes. Front teeth are generally covered with these crowns. They are also durable but not to that extent as metal crowns and may chip more often.
Porcelain-fused-to-metal Crowns
These are a combination of porcelain and metal crowns. The metal substructure is applied and bonded with porcelain. A white-like appearance is provided by these crowns.
These are the most commonly used crowns in dentistry. However, certain resin crowns are available which are inexpensive. However, they are less durable and crack more often.