After reading this thread I must add my two cents. Not that what happened to me is common, but I do want others to be aware of what can or might happen with a bad root canal. I had my first root canal done last December, had a lot of pain, everything you all have been talking about. (Vicodin didn't work, among others....) After weeks of no resolution, and inflamed gums, pain, fevers, etc., several different dentists, endodontists (and three rounds of 10-day antibiotics) I finally made it to a doctor (oral surgeon) at a teaching hospital in a different city, who was finally able to help me by taking a biopsy...and my infection had moved into the bone of my jaw (osteomyelitis) which is why I wasn't getting any better. Bone infections are very serious if left unchecked for long periods of time. Long story short, I had to have surgery to remove the infected bone (fortunately a small area) and then I had to have 6 weekes of IV antibiotics (4x a day, through a pic line in my arm.) I have been an amazingly healthy person my whole life, I'm a fitness instructor, eat healthy, am not overweight or have any illnesses or other conditions that would have predisoped me to an infection. The best advice I can give if you are not getting proper care and resolution is to go to a teaching hospital ideally with a dental school, and go to an oral surgeon or specialist there. It is now May and I am finally going for the crown on that same tooth this week. I am finally feeling back to normal, back teaching my classes, and feeling great. Good Luck!