Methods: 70 non-restored, extracted human premolars were used in this experimental study. The teeth were mounted in 14 plaster blocks. Two blocks were simultaneously used to simulate a bitewing radiograph and digital images were taken by two digital systems: Digora Optime (PSP) at two resolution settings (high and super) and Trophy RVG Access (CMOS) at one. Six observers evaluated 105 proximal surfaces for caries on a 4-point scale in two sessions for each setting. The teeth were sectioned and actual extent of caries was coded on the same scale by an oral pathologist. The results of the histological examination were served as gold standard. Finally, the data were transferred to SPSS version 18 and analyzed using Kruskal-Wallis test; P<0/05 was regarded as significant. Results: There was no statistical difference between the spatial resolution settings assessed in this study for detection of proximal lesions (P>0.05). Overall, Trophy RVG Access showed the highest specificity, 87.7%, and Digora Optime images scanned with high resolution had the lowest specificity, 84.2%.
Conclusions: The results indicated the comparable performance of both digital systems and their three spatial resolution settings in the detection of non-cavitated proximal caries.