ok, I'm an expert on root canals since I've had the same one done 5times cause something keeps ******* up. The shots, do work, you don't feel a thing while it's happening. The dentist will start and if you feel it, ask for a third, I need that sometimes, since I usually have infection in my jaw. The dentist should have a bite guard that you can have, so you don't get scared and clamp your mouth down. After the novacaine wears off the pain where the shots went, does become bothersome so if you can't go to sleep, advil takes all that away. It's not a horror story like everyone says, unless your tooth is cracked in a misterious spot like mine and your dental assistants are little twits who can't stop talking about their boyfriends long enough to help out your dentist....anyways, don't worry about the pain, suck it up and stop being a puss.