Dental crowns are recommended for teeth that are structurally very weak due to the presence of a large filling and little tooth structure. The entire visible surface of the affected tooth is covered by a crown which in turn gives it strength, durability and stability. Crowns are commonly placed on teeth that have had root canal treatment done.
Dental crowns are usually made of ceramic, ceramic fused to metal or metal only depending on the specific requirement of each individual case.
As mentioned earlier, they are also important in bridging gaps.