| As a part of a larger study on new methods for early caries detection in a clinical trial, a radiographic clinical study was done involving 150 children, age 9–12 years. The purpose of the study was to compare direct digital radiographs and film radiographs for detection of approximal caries. Radiographic films (XR) were taken at baseline and 12 months, and direct digital radiographic images (DDR) were taken at baseline, 4 months, 8 months, and 12 months. The direct digital images were captured on Schick sensors (size 1 and 2), and the films on Kodak Ektaspeed Plus. The direct digital images, and the radiographic films were read by two examiners, one using the traditional scoring method (yes/no), and the other using a new detailed scoring method (lesion presence scored on a 5-step confidence scale, and lesion depth in 9 steps). Results were similar for both scoring systems, both examiners detected about 20% more lesions on films. Repeatability was also similar, with Kappa and weighted Kappa in the range of 0.7 to 0.8 for the two scoring systems, respectively. Radiographs were superior to visual examination in finding approximal lesions. Comparisons between the two scoring systems showed numerical differences, but that the main reason was selection of different cut-off points by the examiners. The radiographic readings alone were not sufficient to show a statistically significant difference between treatment groups used in the clinical trial. Validation of radiographic scoring was done on fifty-three exfoliated primary teeth. Histological evaluation done under a stereomicroscope, showed a difference between the methods, with the film scoring being more accurate that the digital image scoring (p = 0.0443). Clinical parameters were also explored, in particular the amount of radiation to the subjects and number of exposures used. Total amount of radiation used in this study was found to be similar to the amount received during regular 6-monthly dental visits over the same time period. In this first direct clinical comparison between these two radiographic methods for approximal caries detection, reading of the traditional films revealed a greater number of lesions than of the direct digital images. |
