You may need a root canal if you have a toothache. The best thing to do in the case of a throbbing toothache is to schedule an appointment with Dr. Gilmor from the Glen Dental Center in Glenview, Illinois who can determine if you need a root canal or a simple dental filling. A root canal is necessary if the pulp, or the inside of your tooth, is infected. The pulp in your tooth is filled with nerves, tissue and blood vessels and if it gets infected your body will do its best to fight off the infection by sending white blood cells to the infected tooth. Swelling is a normal reaction, but because there is not room in your tooth for the swelling, the pulp inside your teeth will begin to die. If this has already occurred, the pain may subside or disappear completely because the tissue has died, and although you may think that the problem has taken care of itself, you are sadly mistaken. If the tissue inside your tooth has died, the infection could cause an abscess. Tooth abscesses are very dangerous and in some cases could mean a trip to the ER.