We reported on the quantitative evaluation of the apical radiolucency. In this experiment, we studied the correlation between the size of apical bone defect and its detectability on the radiograph. We also investigated some factors, that is, the observer's variation and the x-ray film sensitivity.
The mandible phantom with a cylinder-type hole (3mm in diameter) at the apex of mesial root of the first molar was used as a model for the mandible with an apical lesion. We took the radiographs of this phantom, using Kodak Ultra Speed film and Ekta Speed film, and the depth of the hole was changed from 0 to 3.0mm at 0.5mm intervals.
We showed 280 radiographs randomly to 7 experienced and 34 unexperienced observers, and then obtained the answers from these observers concerning their evaluation of radiolucencies in the films.
The results were summerized as follows:
1. The detectabilities of observers were classified into three types, the high, intermediate and low detectabilities.
2. The experienced observers showed a higher detectability on each bone depth. The minimum detectable depth was 1.9mm∼2mm for the experienced observers and 2.3mm∼2.4mm for the unexperienced.
3. The Ultra Speed film obtained a slightly higher detectability point than the Ekta Speed film concerning the detectabilities of observers.
抄録全体を表示