Background: Radiography plays an important role in the detection of secondary caries.These caries are most important cause of changing restorations .The aim of this study was to evaluate the accuracy on diagnosis of secondary caries on esthetic restorations of different materials, changing the incidence vertical angle (IVA) of the x-ray beam. Material and Methods: 40 carious extracted human molars received MOD inlay preparations in vitro study. All teeth were restored with 2 composite resins (Filtek-Z250 and TPH-Spectrum) at 2 moments. Two radiographic images were acquired with 0º and 15º IVA. Four observers evaluated the images using a 5-point confidence scale. Inter, intra-observer reliability was analyzed with the Interclass Correlation Coefficient and the diagnostic accuracy was evaluated using the area under the ROC curve (Az), Friedman test and Wilcoxon test (α=0.05). Results: Higher accuracy values were obtained with 15º IVA (Az=0.65, Filtek-Z250>Az=0.56, TPH-Spectrum) compared to 0º (Az=0.50, Filtek-Z250>Az=0.37, TPH-Spectrum), though without statistically significant difference (p>0.05). Conclusion: Changing the IVA of the x-ray beam has no negative influence on the diagnosis of secondary caries-like lesions simulated on ethetic restraction of different materials.