Visualization of stannous fluoride treatment of carious lesions by subtraction radiography

To determine whether treatment with SnF2 results in changes in radiographic density, eight extracted teeth with lesions confined to the enamel and five with lesions extending into the dentin were radiographed before and after treatment with a 10% SnF2 solution. Although visual comparison of pretreatment and post-treatment radiographs showed increased density in some areas where the pretreatment radiographs had shown demineralization and unchanged conditions in other instances, subtraction images of these radiographs revealed density increase in all the demineralized areas. Even in cases with white spot lesion not visible on radiographs, the subtraction images disclosed an increase in radiographic density.