Efficacy of the Edge Enhancement Filter of Digital Radiography in the Detection of Proximal Enamel Caries in Premolars

Background and Aim: Considering the significance of the detection of proximal caries and the limited information available on the diagnostic value of digital radiography after the use of enhancement filters, this in-vitro study sought to compare the diagnostic value of digital radiography with and without the use of the edge enhancement (EE) filter in the detection of proximal enamel caries in premolars. Materials and Methods: This in-vitro study was conducted on 80 extracted intact human premolars. Every two teeth were mounted in a single block using putty impression material and every two blocks were placed in articulation. Digital bitewing radiographs were taken and saved twice, once in their original form and once after the application of the EE filter. Afterwards, a cavity was prepared on the proximal surface of one of the teeth (chosen randomly) in each block using a bur and then, the tooth was put back in the block. Digital bitewing radiographs were taken again with the same exposure settings. The 80 final images were printed on radiographic films and were evaluated by three oral and maxillofacial radiologists. The results were compared with the gold standard (the cavities formed by a bur). The data were statistically analyzed by Chi-square test. Results: The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy were 75%, 87.5%, 85.7%, 77.7% and 81.2%, respectively in the original digital radiographs and 80%, 95%, 94.1%, 82.6% and 87.5%, respectively in the enhanced images. The difference between the two groups was not statistically significant (P=0.7, P=0.3, P=0.3, P=0.7, P=0.3). Conclusion: Application of the EE filter does not improve the diagnostic accuracy of radiographs in the detection of proximal enamel caries.