A root canal can sometimes be a dental emergency and sometimes the root canal can be done at a later appointment date.
It depends on how severe the tooth problem is to warrant the need for a root canal.
Most times though when you need a root canal it will be considered an emergency procedure and the dentist will perform the root canal right away.
A root canal is the dental treatment for an abscessed tooth or tooth that has broken off into the inside part of the tooth called the pulp.
A tooth that has broken into the pulp or a tooth that is knocked out of the mouth is a dental emergency and in that cases the root canal is a dental emergency.