Having an abscessed tooth can be a very painful experience and requires urgent attention when it occurs. The condition occurs when a pocket of pus in the tooth has led to an infection. The infected tooth may cause a persistent toothache, tender lymph nodes in the neck, fever, tooth sensitivity to hot and cold, a pimple-like bump on the gums near the infected tooth and swelling in the face. An abscessed tooth is considered a dental emergency because the infection can spread into the jaw, surrounding tissue and to other parts of the body. Before seeking emergency dental care, the pain can be alleviated by rinsing the mouth with mild saltwater several times.