A dental crown serves to solidify a tooth and maintain its integrity after it has suffered destruction, either from tooth decay or from a trauma. A tooth that must get a root canal probably already had a very large cavity that had reached the pulp chamber where the nerve is located. After the dentist had properly cleaned the tooth from all decay and that the root canal treatment is completed, there usually doesn’t remain sufficient healthy dental material to restore the tooth with a filling. It is then necessary to complete the treatment by a post and a dental crown to ensure that the tooth will not break eventually.
There are however certain situations where a tooth’s nerve is irritated after a trauma and not because of a destructive dental cavity. If the tooth that had the trauma is not broken or cracked, and if it did not already a big filling, then it may be possible to do a root canal treatment and maintain the integrity of the tooth. In this case, a filling is sufficient to restore such a tooth without needing a crown.
The information above should be used as a reference only. Any medical decision should not be taken before consulting a health care professional.