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.
Melo
D P
DP
Department of Oral Diagnosis, Division of Oral Radiology, Piracaba Dental School, Campinas University, UNICAMP, Piracaba, Brazil. danipita@fop.unicamp.br
Dos Anjos Pontual
A
A
de Almeida
S M
SM
Campos
P S F
PS
Alves
M C
MC
Tosoni
G M
GM
D003743:Dental Enamel / Q000000981:diagnostic imaging; D003804:Dentin / Q000000981:diagnostic imaging; D017743:Equipment Reuse; D006801:Humans; D008027:Light; D016015:Logistic Models; D019252:Radiography, Dental, Digital / Q000295:instrumentation*; D013997:Time Factors; D014963:X-Ray Intensifying Screens