Efficacy of different undiluted fixing solutions in lightening

Dental radiographs are darkened in some cases due to overexposure, high concentration of developing solution etc. The aim of this study was to evaluate the effect of various undiluted fixing solutions on decreasing the density of dark radiographs. In this analytical cross-sectional study, 95 periapical radiographs were taken from the first mandibular molar of a dry skull. One film was developed under optimal conditions and considered as gold standard or the positive control; 93 films were overexposed to enter the study. The last film was overexposed, was not included in the study and was considered the negative control to compare the effect of fixing agent. All the radiographs were processed automatically under the same conditions. Then the overexposed radiographs were divided into three equal groups of 31 radiographs. Each set was immersed in different undiluted fixing solutions, including Champion, Cronex, and Teif Saz. Finally, the densities of radiographic films were assessed objectively by a densitometer and subjectively by obtaining questionnaires from observing dental practitioners. Data was analyzed by ANOVA and Duncan test (α = 0.05). The densities of all the radiographs had significantly decreased after immersion in undiluted fixing agents. Furthermore, improvements in diagnostic quality of the darkened radiographs were significant due to the effect of undiluted fixing agents (p value < 0.001). Generally, the undiluted fixing solution is a suitable agent to decrease the density and restore the diagnostic quality to dark radiographs, preventing re-exposure of patients and avoiding extra costs.