Preparing the Tooth. If you need a crown, you may also need endodontic or root canal treatment on the tooth. Not everyone who needs a crown will also need a root canal. Root canal treatment is required if the cavity is deep and reaches the pulp of the tooth, where the nerve of the tooth is located.ou shouldn't feel any discomfort or sensitivity after a crown is placed. However, if your tooth has not had a root canal, it will still contain the nerve. You may therefore have some temporary sensitivity to cold. If you notice pain or sensitivity when you bite down, contact your dentist.