I don't that much about dentistry,or what the exact nature of the condition known as root canal is,however I find it counter intutitive to imagine an infant with root canals.
This depends on the tooth and the age of the child. My daughter, at 2, received root canals, while sedated in the hospital for the work. My nephew at 3 1/2 had a tooth pulled and a spacer put in while sedated in a hospital.