One of the limitations of Direct Digital Radiography (D D R) is noise. The use of digital image processing has gained acceptance in dental diagnostic science. Numerous recent publications have indicated that Digital subtraction Radiography (D S R) might significantly aid in the clinical diagnosis of dental diseases, once various clinical logistic problems limiting its widespread use have been over-comed. Noise in digital radiography may result from sources other than variation in projection geometry during exposure. Structure noise consists of all anatomic features other than those of diagnostic interest. Limitations of plain radiographs in detecting early, small bone lesions are also due to the presence of structure noise. This study has been under-taken in an attempt to minimize structure noise in digital dental radiography by using digital subtraction radiography.