Dental radiography has long been considered useful in the diagnosis of periodontal disease, it was employed in epidemiological studies in longitudinal studies, in the morphological and volumetrical evaluation of bone lesions and in the diagnosis and prognosis of periodontitis. However the radiographic technique and its interpretation were not always accurate. We can divide the evolution of the radiographic interpretation of periodontitis in three periods: the first period is comprised from the early years of the periodontal science to the seventies; in this period in spite of the evolution of the radiographic technique, there wasn't a standardization of the diagnostic criteria because of the un-understanding of the etiopatogenesis of periodontitis. In the second period, that is comprised from the seventies to the present, the understanding of the etiopatogenesis and of the evolution of periodontal breakdown, made possible the standardization of trials and diagnostic criteria and the fixation of limitations and indications of the radiographic interpretation of periodontitis. The third period, that is a prospect for the future as clinical application, at the present has application only in research. In this period use of new techniques, as scintigraphy and computerized analysis of radiographic image, made possible an higher sensibility of the radiographic technique.