Influence of Image Filters and Variation in Horizontal Angle of Incidence of X-ray Beam in Digital Interproximal Radiographs for Diagnosis of Secondary Caries in Esthetic Restorations.

Secondary or recurrent caries are located around restoration margins or under these lesions, and can lead to tooth loss. The interproximal or bite wing radiograph is the technique of choice to assist diagnosis of secondary caries.

To evaluate diagnostic accuracy of secondary caries in pulpal walls artificially created in extracted human premolars, observed in digital bitewing radiographs using variations in horizontal X-ray beam angle of incidence and application of enhancement filters.

The sample consisted of 20 healthy premolars, in which secondary caries lesions were simulated by means of subjecting the pulpal wall of the cavity to wear with spherical carbide drill half, fitted to a high speed handpiece, under constant cooling, focused perpendicular to the tooth surface. The orifices were filled with wax and all teeth were restored with composite resin Filtek Z350 XT(®). Later teeth were radiographed with a digital sensor complementary metal-oxide-semiconductor (CMOS) varying the horizontal angle at intervals of 2°, covering a range of -10 to +10°.

The results showed that in the diagnosis of secondary caries, there was no statistically significant difference between the 2 pseudocolor filters, and negative and direct digital radiography. The pseudocolor filter no. 1 showed statistically significant differences, except at a horizontal angle of 0°, thus indicating lower efficiency in the diagnosis of secondary caries.

Secondary caries with esthetic pulp wall restoration can be diagnosed irrespective of variation in the horizontal angle of incidence of the X-ray beam. The use of different radiographic enhancement filters did not result in improved diagnosis of secondary caries.