A comparison of the diagnostic accuracy of bitewing, periapical, unfiltered and filtered digital panoramic images for approximal caries detection in posterior teeth.

OBJECTIVES: The aim of this study was to investigate the diagnostic accuracy of conventional bitewing, periapical radiographs, unfiltered and filtered digital panoramic images for the assessment of approximal carious lesions in posterior teeth. METHODS: 20 patients who required bitewing, periapical and panoramic radiographs participated in the study. The digital panoramic images were treated with the "sharpen", "smooth" and "emboss" filters. Three experienced observers evaluated the bitewing and periapical radiographs, and the unfiltered and filtered digital panoramic images for the presence or absence of approximal carious lesions according to a 5-point confidence scale. Intra- and interobserver reliability was analysed with the Cronbach alpha test and diagnostic accuracy was evaluated using receiver operating characteristic (ROC) analysis. RESULTS: According to the results, the intra- and interobserver agreement levels were found to be almost perfect. The highest diagnostic accuracy was found for the bitewing, followed by the periapical and panoramic images. Compared with the unfiltered panoramic images, the filtered images had an almost equal or slightly higher diagnostic accuracy. The largest increase in diagnostic accuracy was observed for those images filtered with the emboss filter. CONCLUSIONS: The accuracy of unfiltered and filtered digital panoramic images is lower than conventional bitewing and periapical radiographs. The filtration of the digital panoramic images, especially the emboss filter, may have some value for the detection of approximal carious lesions.

The precision of the panoramic mandibular index.

OBJECTIVES: This study evaluates the precision of the panoramic mandibular index (PMI). MATERIALS AND METHODS: Measurements were made by two observers on both of the left and right sides of the mandible on the radiographs taken from 41 young individuals and the inferior and superior PMI were calculated. Two weeks later the same observers repeated their measurements to assess intrarater reliability. Paired t-test, Pearson correlation coefficients and precision values were calculated to assess levels of association. RESULTS: There was a significant difference between the first rater's first and second measurements (intrarater repeatability) for both the inferior and superior PMI, while no significant difference was observed for the second rater. The intrarater and inter-rater precision values for the inferior PMI were calculated as 0.005319 and 0.005594 for the first rater and 0.005663 and 0.005594 for the second, respectively. The intrarater and inter-rater precision values for the superior PMI were similar for both observers, calculated as 0.002558, 0.002766; and 0.003046, 0.002766, respectively. The precision of both inferior and superior indices was not very good, but precision figures for the superior PMI demonstrated consistency almost twice better than those for the inferior PMI for both observers. CONCLUSIONS: The precision values for the PMI seem to be sufficient according to the results of this study, but they are still questionable and more studies need to be done on this aspect.