Reproducibility of Subtraction Radiography in Monitoring Changes in Approximal Carious Lesions in Children: An In Vivo Study

BACKGROUND: Laboratory studies have shown that digital subtraction radiography (DSR) can be a more effective tool, than conventional radiography, in monitoring changes in carious lesions. The clinical performance of the technique, however, has not been sufficiently researched. AIM: To compare the reproducibility of DSR to that of bitewing radiographs, in monitoring changes in approximal caries in the mixed dentition. A secondary aim was to determine if assessment outcomes differed as a function of the method used. DESIGN: Six assessors evaluated 310 lesions first on bitewings, then with DSR. The overall reproducibility was evaluated via intra-class correlation coefficient (ICC). Intra and inter-rater reproducibility, were assessed using weighted Kappa. Paired t-test was used to assess differences in the reproducibility across methods. RESULTS: The overall reproducibility for DSR was (ICC=0.47, 95% CI=0.31-0.56). Intra and Inter-rater reproducibility were (0.65, 0.44) respectively. The overall reproducibility for bitewings was (ICC=0.45, 95% CI=0.42-0.57). Intra and Inter-rater reproducibility were (0.71, 0.46) respectively. Differences in the reproducibility across methods were not statistically significant. Significantly more lesions were scored as progressed using DSR. CONCLUSIONS: The reproducibility of DSR in monitoring changes in approximal caries, is comparable to that of bitewings. Additionally, DSR detected higher proportion of progression than bitewing assessments.