Objective and subjective comparisons of the observation of dental xeroradiographs with reflected and transmitted...

One of the advantages of dental xeroradiography is that the radiographs may be viewed by either reflected or transmitted light. Both objective and subjective evaluations were carried out to evaluate which viewing method was more efficient. The components of contrast, resolution, and noise were compared by objective physical evaluation. The subjective evaluation measured the visibility of radiographic details. All results of the objective evaluation indicated an advantage for observation with reflected light. On the other hand, the subjective evaluation with transmitted light demonstrated better detectability. The discrepancy of these results could be explained by the difference in the amount of incident light on the radiographs, when a comparison was made of the same subjective evaluation under intense reflected light with the use of slide projectors.