Root canals get a bad wrap. But don’t believe the rumors; the dreaded root canal isn’t dreadful at all! Root canals are needed when either decay or an injury infects the inner tooth (the pulp). In the earliest stages of infection, you may not feel any pain at all. But when it progresses, you could have a toothache and swelling, or a dental abscess might form. Root canals remove the infection and prevent it from spreading. Pulp capping is an alternative to root canals that are used when the infection has yet to penetrate the pulp. Pulp capping can also prevent a large dental filling from getting too close to the nerve.