Validation of a specific selection criterion for dental periapical radiography.

It has been recommended that the prescription of dental radiographic examinations be based on a series of selection criteria. This study evaluated the usefulness of the presence of a large or deep restoration as an indicator for the need for a radiographic examination. Patients in need of routine examinations were questioned regarding pain in restored teeth. The radiographs of 2269 restored teeth in 209 patients were evaluated for depth of restoration and presence or absence of periapical pathosis. Another 1306 nonrestored teeth in 100 patients were evaluated similarly. There was an association between pain and periapical pathosis and between depth of restoration and periapical pathosis (p < 0.001 in each case). Radiographic yield for positive apical findings was low in restored teeth, especially when the restoration was shallow. The radiographic yield may be increased if other factors such as pain or integrity of the restoration are used to help make the decision regarding the need for radiographs.