Radiographic identification of simulated carious lesions in relation to fillings with Adaptic Radiopaque

The purpose of the present study was to elucidate the possible significance of the radiopacity of a composite restorative material for the radiographic identification of filling deficiencies. Class III cavities of varied size and shape were prepared at 28 proximal surfaces of 14 extracted human canines. All cavities were filled with Adaptic Radiopaque. Simulated secondary or recurrent carious lesions were produced in 16 of the cavities by insertion of small amounts of radiolucent wax prior to filling. Each tooth was radiographed under standardized conditions using 15 different angulations. The 210 radiographs were interpreted by three observers without knowledge of the distribution of the deficiencies. They made 78.7% correct diagnoses, 18.7% false positive and 2.6% false negative diagnoses. The sensitivity of the method was 95.4, but the specificity was only 56.5. The results indicate that radiopacity of a composite resin is of a certain, although limited, value in detecting secondary and recurrent carious lesions. Regarding the high number of false positive diagnoses the radiographic findings should as far as possible be verified by a clinical examination. A majority of the false positive diagnoses could be explained by an inhomogeneous structure of the fillings.