Our aim was to investigate the DenOptix system for detection of proximal caries using alternative erasing times for the photostimulable phosphor plates. Human teeth were X-rayed with phosphor plates using different erasing times. Five observers evaluated the images for the presence of caries by scoring the proximal surfaces of each tooth. Mean pixel intensity analyses were also carried out. The erasing times were evaluated using receiver operating characteristic (ROC) curve analysis. Analysis of variance for differences among erasing times and pixel intensity values was performed, followed by linear regression analysis for correlation between these variables. The mean ROC curve for each erasing time varied from 0.61 to 0.66 (not significant). Analysis of variance did not show any significant effect of the erasing times on the pixel intensity values of the images (P > .05). Erasing times for DenOptix phosphor plates from 20 to 130 s were satisfactory for diagnosis of proximal caries, and their use is therefore feasible in clinical practice.107122-6