A swollen, pus-filled area on your gum near a tooth that throbs with pain may indicate you have an abscess. Further determination of an abscess can include pain on the affected side while eating. If the pain was severe enough you may have already made an appointment to see your dentist. If the infected area on your gum should burst, rinsing with warm salt water may help. The warm salt water will not only soothe your gums but also wash away the pus. Be sure to seek treatment even after the infection bursts. If the cause of your abscess is left untreated, it can continue to damage the supporting tooth bone. Without proper support the tooth may become loose, fall out, or need removal. Your dentist may perform a root canal to save the tooth or extract the tooth if it's not possible to save it. The best treatment of an abscess is to prevent them with good oral hygiene. Remember to see your dentist regularly for professional cleaning and an examination.