Clinical evaluation of a samarium/aluminum compound filter

Rare earth compound filters, which offer reduced patient exposure during intraoral radiography, have not been clinically evaluated for their effect on diagnostic yield. This clinical study was conducted to compare the diagnostic yield of bitewing radiographs exposed with a conventional aluminum filter with matched bitewing radiographs exposed with a samarium/aluminum compound filter. One hundred sixty-three pairs of bitewing radiographs were read independently by two reviewers for absence or presence and depth of proximal carious lesions. Degree of agreement between films was assessed by means of the kappa statistic. Results showed good agreement between the radiographs exposed with each filter type. Thus, x-ray machines modified with a samarium/aluminum rare earth compound filter produce bitewing radiographs of comparable diagnostic yield and lower dose when compared with radiographs exposed with a conventional aluminum filter.