In vitro comparison of high-definition US, CBCT and periapical radiography in the diagnosis of proximal and recurrent caries

Abstract

Objective: To assess the in vitro performance of high-definition (HD) US, CBCT and periapical radiography for the visibility of proximal and recurrent caries in teeth with and without restoration. Methods: A total of 240 molar teeth were divided into eight groups each comprised of 30 teeth. Control groups consisted of teeth without caries (Group 1–4; N = 120), whereas diseased groups consisted of teeth with proximal caries (Group 5–8; N = 120 teeth). Finally, a total of four image sets were obtained as follows: i) PSP periapical radiography, ii) CBCT 0.075 mm voxel size, iii) CBCT 0.2 mm voxel size and iv) HD US images. The image sets were viewed separately by four observers by using a 5-point confidence scale. Intraclass correlation coefficients were calculated. The areas under the ROC curves were compared using chi-square tests. Significance level was set at α = 0.05. Results: Intraobserver agreement for both readings for the four observers ranged between 0.848 and 0.988 for CBCT (0.075 mm) images; 0.658 and 0.952 for CBCT (0.2 mm) images; 0.555 and 0.810 for periapical images; 0.427 and 0.676 for US images. Highest AUC values were found for CBCT (0.075 mm) images and lowest for US images. Statistically significant differences were found among CBCT (0.075 mm) images and US images (p < 0.001), CBCT (0.2 mm) images and US images (p < 0.001) and periapical images and US images (p < 0.001) for the detection of proximal caries. Conclusion: Periapical and CBCT images outperformed HD US imaging in the detection of proximal dental caries.