Effect of alternative photostimulable phosphor plates erasing times on subjective digital image quality.

OBJECTIVE

To evaluate the influence of alternative erasing times of DenOptix(R) (Dentsply/Gendex, Chicargo, IL) digital plates on subjective image quality and the probability of double exposure image not occurring.

METHODS

Human teeth were X-rayed with phosphor plates using ten different erasing times. Two observers evaluated the images for subjective image quality (sharpness, brightness, contrast, enamel definition, dentin definition and dentin-enamel junction definition) and for the presence or absence of double exposure image. Spearman's correlation analysis and ANOVA was performed to verify the existence of a linear association between the subjective image quality parameters and the alternative erasing times. A contingency table was constructed to evaluate the agreement among the observers, and a binominal logistic regression was performed to verify the correlation between the erasing time and the probability of double exposure image not occurring.

RESULTS

All 6 parameters of image quality were rated high by the examiners for the erasing times between 25 s and 130 s. The same erasing time range, from 25 to 130 s, was considered a safe erasing time interval, with no probability of a double exposure image occurring.

CONCLUSIONS

The alternative erasing times from 25 s to 130 s showed high image quality and no probability of double image occurrence. Thus, it is possible to reduce the operating time of the DenOptix(R) digital system without jeopardizing the diagnostic task.