When a deep cavity, decay or crack destroys these protective layers of the teeth, the pulp is exposed to the bacteria in your mouth. This can result in inflammation, infection and, eventually, necrosis (pulp death). A severe blow to the tooth can also damage the pulp. Irritants may then escape from the end of the root and cause a diseased area (apical lesion) in the bone. The procedure involves removing the inflamed or damaged tissue from inside a tooth and cleaning, filling and sealing the remaining space. An examination, including radiographs, will be performed. A local anesthetic will be given, if necessary.