A dental crown is a very specialized, customized cover that sits on top of your tooth, covering it from all sides and making sure that an inert environment is created inside. This stops the bacteria from growing in the tooth, as well as any food particles sticking between teeth. A dental crown is only applied on a tooth after it is thoroughly cleaned. Usually, dental crowns are the final part of a root canal procedure, where the entire pulp and nerves of a tooth are drilled through, and filled with a dental filling. The crown is then adjusted to make sure that the tooth stays in place and firm.