Densitometric analysis of experimentally produced periapical radiolucencies.

Artificial periapical lesions were created in a mounted dried human mandible. These lesions were radiographed by means of a reproducible projection technique. A penetrometer was projected on the same radiographs as the dental and bony structures. The developing process was standardized. The radiographs were evaluated by means of densitometric analysis. The densitometer readings of the dental and bony structures on the radiographs were converted to a millimeters-of-aluminum-equivalents scale by means of the densitometer readings of the penetrometer images on the same radiographs. The measurements on the radiographs were presented in graphs and isodensitometric images. Areas where bone was removed could be reproducibly distinguished by densitometric analysis from areas where no bone was removed. For this purpose, the densitometric analysis of periapical radiographs proved to very useful, whereas the interpretations of the same radiographs by ten dentists differed greatly.