The Effects of Infection Control Techniques on PSP Digital Sensor Image Quality

Research has demonstrated that the barrier envelope used with the photostimulable phosphor (PSP) receptor in dental digital imaging is not completely effective in the prevention of cross-contamination of the PSP receptor. Objective: The purpose of this study was to determine the effects of disinfection and sterilization techniques on PSP receptor image quality. Methods: Twenty new PSP receptors were randomly assigned to 4 treatment groups following verification of comparable densities: control group (no treatment), ethylene oxide group, alcohol disinfection group (receptor disinfection), and the Prophene^TMplus group (barrier envelope disinfection). Each PSP was exposed using an XCP bitewing holder and a phantom at 66 kVp, .06 time, and 8mA. Overall density measurements and a contrast index were measured on each receptor at baseline using NIH Image software. Exposures and disinfection/sterilization treatment procedures were then repeated for each sensor a total of 50 times. Measurements of overall density and contrast were made after the following exposure cycles: 1st, 10th, 25th, and 50th. Data were analyzed using a repeated measures analysis of variance test. Results: No statistical difference (p>0.05) was observed in overall density among the four groups, although mean density values increased from the first to fiftieth exposure cycle (91.9-105.8). The contrast index for all groups displayed an initial drop in value after the first cycle, but then increased over time (p=0.2), although the index value at the fiftieth exposure cycle (54.5) was lower than the baseline value (59.0). Conclusion: It appears that disinfection/sterilization methods do not influence the image quality of the receptors and that the change in contrast may be attributed to scanner variation or increased exposures to ionizing radiation or scanner laser. Further investigation is warranted concerning scanner calibration.