Root canal is a no no in my world of health.
Root canal is meant to be a bread and butter of dentists. It only benefits the dentist monetarily but not the patients.
If the tooth is doomed, extract it.
This is my stand on root canal:
"All root canals must be extracted. Root canalled teeth are dead teeth and have no business being stuck in your jaw causing illness. If you want to get well, this must be done now."
http://www.curemanual.com/detox-protocols/dental-cleanseYou can compromise with your mom and stick with raw fish for the moment.