Many times the infection in a tooth that requires the root canal procedure has spread into the bone surrounding the tooth and causes a residual pain until the infection has been successfully eliminated. Taking an antibiotic can hasten the resolution, as can eating a normal diet, avoiding too much sugar, getting enough rest. An infected tooth is not to be trivialized. The site is within inches of the brain. Take care of yourself-don't over-do. And get immediate follow-up care if things seem to continue getting worse-don't wait until Monday.
Posted by Steve