A periapical abscess is cavity filled with pus, located in the gum tissue near the tip of a tooth's root. It is most commonly caused by an infection in the gum tissue that causes the pulp to die. Fluids, dead white blood cells, necrotic tissue, and waste materials build up in the infected area and force their way through the area that contains the tooth's blood vessels and nerves, the apical foramen. The pus and dead tissue will continue to try to escape by forcing its way through the soft tissue and tooth socket, creating a sinus tract and causing a condition similar to a nasal abscess.
These abscesses can cause facial swelling, toothaches, a bad taste in the mouth, and enlarged or tender lymph nodes. Swelling is caused by the expansion of tissue as it is invaded by pus and other fluids. Large amounts of swelling is known as cellulitis, while small spots of swelling near the sinus tract is called a gumboil.
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The bad taste that is sometimes related to a periapical abscess is caused by fluid leaking out of the sinus cavity or abscess. Toothaches are the result of the tissue around the tooth's nerve endings dying, which can also cause the tooth to move slightly in its socket when it is touched. Enlarged or tender lymph nodes are the body's reaction to an infection, especially a local infection.
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When an abscess is caught early enough, it is easily treated with antibiotics and draining. Left to fester too long, however, it can result in the need for a root canal or the complete loss of the tooth. A periapical abscess needs be treated as soon as possible in order to save the tooth.
Whenever swelling and tenderness is found at the base of a tooth, a dentist should be consulted. A periapical radiograph can be done that will effectively diagnose the problem to see if an abscess is present. Once a toothache begins to occur, the gum tissue is usually dead and a dentist will have to work quickly to save the tooth.
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Many people confuse a periapical and a periodontal abscess because they both affect the gums, jaws, and areas around the teeth. A periodontal abscess is much more benign and will normally cause little damage beyond a cavity in the tooth. A periapical abscess, however, is dangerous and should be taken care of immediately.