Diagnostic Efficacy of Digital and Conventional Radiography in Periapical Bone Lesions

The only sign of chronic apical periodontitis is periapical lesions that are seen in radiographs. Lesions are visible when the inflammation reaches cortical plates. Lesions located in cancellous bone, cannot be easily seen in radiography. Developing computerized technology in radiography, which has numerous advantages and its show up devices in the market, encourage the clinicians to take advantage of this technology. It has accessory image processing softwares such as color spectrum. Most currently available systems provide facilities for color conversion of gray scale images. Humans can distinguish much more colors than shades of gray. The aim of this study was to evaluate the diagnostic efficacy of color conversion in diagnosing the periapical lesions located in cancellous bone. 10 premolar teeth were placed in bony sections of the cadaver mandibles. To make sure that there hasn’t been any periapical lesions in sections previously, conventional radiographs were taken. In the next step, simulated periapical lesions were prepared artificially in the buccal or lingual cancellous bone. Then, direct and indirect conventional and digital images were taken. Digital black and white images were converted to colored images using the image processing system. Five observers were asked to determine the presene, location and size of the lesions. Statistical analyses revealed that color conversion of digital radiography is more accurate than black and white white digital and conventional radiography in determining the presence, location and size of the lesions. In conclusion transforming the gray values of digital images into a color spectrum can improve the detection of bone loss. This is a usefull tool for diagnosing the lesions located in cancellous bone.