We have already compared Patterson's intensifying screens and Kyokko intensifying screens on the basis of intensifying coefficient as well as the method of examination of sharpness used by K. Wiiratlin. Also, we have made comparison of all domestic screens while improving our ways of estimation. However, all these methoes are not simple, and accordingly necessitate special apparatuses or instruments. In the present report, an easy and practical way of estimating qualities of intensifying screens and its application are explained. The method is to simply radiograph using an X-ray apparatus.
With the recent rapid progress of manufacturing technique, the importance of various kinds of planigraphic apparatuses has widely been recognized. In this paper, the results of experiments, testing the superposition of X-Ray images of various planigraphic apparatuses, a measuring device experimentally assembled under certain conditions, are reported.
We changed the voltage of X-ray tube according to conditions of potients. Especially, we made experiments to show up shadows of cavities. We obtained satisfactory results. Therefore it reports the practical facts and comparison between the conditions of shadows of cavities obtained by the radiographing and the clinical conditions.