A periapical x-ray is a closeup of a particular tooth or teeth. If your dentist recommends one, by all means, have him take it. I recommend periapical x-rays to my patients anytime they say that they are having pain in a particular area, if there is deep decay in a tooth or if there is a problem or defect that is apparent on a bitewing x-ray (the x-ray that is used to detect cavities and gum disease) but cannot be seen in it’s entirety. When viewing a periapical x-ray, the dentist will look at the bone around the root, the height of the bone for periodontal (gum) defects, intactness of the root and for any other pathology (disease process) that could be visible. If a darker area exists on the x-ray around the tip of the root, then that could mean that there is a dead nerve inside the tooth. Dark areas up the side of the root could mean a possible root fracture. Dark areas at the crest of the bone (the portion closest to the crown of the tooth, i.e. the part of the tooth that you see) is usually an indication of bone loss due to gum disease. Pathological conditions can show up as either light or dark areas. This could be indicative of a tumor or cyst. That’s why it is so important to allow your dentist to take a periapical x-ray if he recommends it.