Influence of interpretation conditions on the subjective differentiation of radiographic contrast of images obtained with a digital intraoral system.

ABSTRACT

OBJECTIVES: The aim of this study was to evaluate interpretation conditions in the subjective in vitro assessment of dental tissue-equivalent radiographic contrast. STUDY DESIGN: Radiographic images with the density of dental structures were randomized and arranged in 20 sequences with images juxtaposed and separated. Twelve observers interpreted the sequence among the most radiolucent and radiopaque images with 3 displays, 3 horizontal viewing angles, and 3 ambient light conditions. The evaluation time was recorded. The hit percentage was calculated for each evaluation. Three-way analysis of variance with Tukey's test was used to compare the conditions of interpretation. The intraclass correlation coefficient was used to assess agreement (α = 0.05). RESULTS: No differences in hit percentages were found among the 3 displays or among the juxtaposed and separated images. Increased hit percentages were recorded for images assessed at 90° compared with 45° for all displays and in high ambient light vs intermediate and low light at 90°. Increased evaluation time was recorded for the consumer-grade display under high ambient light and for the separated images. CONCLUSIONS: The subjective in vitro assessment of dental tissue-equivalent radiographic contrast is not influenced by computer display, which should be viewed at a horizontal viewing angle of 90° and under high ambient light. Longer evaluation times may be expected with consumer-grade displays.