Cross-contamination of the PSP sensor in a preclinical setting

This study tested an infection control protocol for photostimulable phosphor (PSP) sensors while simulating multiple uses.

Dental hygiene students (n=36) were randomly assigned to a control group (dry wipe) or test group (disinfectant wipe). A sterile, barriered sensor was placed in a peer patient's mouth to simulate an exposure. After simulation, the barriered sensors were disinfected, placed into a new barrier, and inserted into the same peer patient's mouth. Following the fourth placement and treatment, sensors were vortexed in specimen cups containing trypticase soy broth (TSB) and incubated at 37 degrees C to detect contamination by oral bacteria.

Bacterial growth in TSB was monitored as a change in optical density and by quantitation of oral streptococci on Mitis-salivarius agar. The barrier-protected sensors were minimally contaminated (<10(5) colony forming units/ml at baseline) regardless of treatment. After culture amplification, the control TSB had more samples that remained negative through 48 hours (5/18 vs. 0/18 for test group, p<0.05).

Barrier envelopes used with the PSP sensors appeared to be an effective way of reducing microbial contamination.