An ex vivo comparison of conventional and digital radiography for perceived image quality of root fillings

To compare the subjective image clarity of two different speed films and the Digora phosphor plate images with respect to the length and homogeneity of root canal fillings.

Root canal treatment was performed on 20 extracted permanent mandibular first molar teeth. Standardized images of each tooth positioned in a dried mandible were obtained with E- and F-speed films and Digora storage phosphor plates (SPP) at 0 degrees and 30 degrees horizontal angulations using the optimal exposure time recommended for each system. Five endodontists and five radiologists rated the image clarity of E- and F-speed radiographs as well as the original and enhanced Digora images. The data were compared using the Wilcoxon signed rank test (P < 0.01). Inter-observer agreement was determined by Cohen's kappa.

Enhanced digital images were rated as superior followed by E- and F-speed films and then the original digital images for the evaluation of both homogeneity and length (P < 0.01) of root canal fillings. Agreement among endodontists and radiologists measurements was high in all of the imaging methods (kappa = 0.87).

Perceived image quality of the enhanced Digora images was superior to the original Digora and conventional film images for the evaluation of root fillings. However, E-speed film provided a significantly better image clarity in comparison with F-speed and original Digora images.