Influence of tube potential setting and dose on the visibility of lesions in intraoral radiography

Abstract

The objectives were to determine the diagnostic accuracy of different image receptors when first, the tube potential setting was increased from 60 kV to 90 kV and second, when the milliampere setting was reduced at unchanged tube potential for storage phosphor plates. Intraoral radiographs (films of speed class F, storage phosphor plates) were taken of 12 dried human skulls prepared with lesions in both teeth and peri-implant bone, in ascending size. Five observers assessed the presence (response=1) or absence (response=0) of lesions. The digital intraoral radiograph was exposed at 60 kV and 90 kV with half and a quarter of the film exposure. Some of the radiographs were assessed a second time. In total, 6000 assessments were made. Intrarater agreement was expressed by Cohen's kappa coefficient. The digital combinations showed the lowest diagnostic accuracy in all combinations, but the results demonstrated an equivalence of all combinations of films and storage phosphor plates. The differences in diagnostic accuracy were low (94-96.5%). The kappa coefficient for intrarater agreement was high (0.85). Regarding peri-implant and decayed lesions, intraoral films and storage phosphor plates demonstrated equal quality in this in vitro study regardless of exposure at 60 kV or 90 kV.