Root canal treatment (endodontics) is a dental procedure used to treat infection at the center of a tooth. Root canal treatment is needed when dental x-rays show that the pulp has been damaged by a bacterial infection. The pulp may become inflamed if it's infected by bacteria, allowing the bacteria to multiply and spread. The symptoms of a pulp infection include: pain when eating or drinking hot or cold food and drink pain when biting or chewing a loose tooth As the infection progresses, these symptoms often disappear as the pulp dies.