An abscessed tooth is an infection caused by tooth decay, periodontal disease or a cracked tooth. These problems can let bacteria enter the pulp (the soft tissue of a tooth that contains nerves, blood vessels and connective tissue) and can lead to pulp death. When pus builds up at the root tip in the jaw bone, it forms a pus-pocket called an abscess. If the abscess is not treated, it can lead to a serious infection in the jaw bone, teeth and surrounding tissues. Symptoms of an abscess include: pain swelling redness in the gums bad taste in the mouth fever An abscessed tooth can be treated with various treatments, depending on the severity of the infection. Here are some of the treatment methods a dentist may …