Evaluation of aluminum-yttrium filtration for intraoral radiography

In comparison with the use of traditional aluminum filtration, a radiation dose reduction of 40% at 90 kVp and 25% at 70 kVp was found with the use of aluminum-yttrium (Al-Y) filtration for intraoral bitewing and periapical radiographs. An increased exposure time, and consequent greater tube loading, was necessary to maintain film density. Extended gray-scales (i.e., reduced radiographic contrast) occurred at both energy levels tested with the use of Al-Y filtration. Subjective evaluation of image quality in terms of clarity, resolution, and contrast was carried out independently by nine periodontologists. Despite some interoperator variance, there was a preponderant preference for traditional aluminum filtration.