Peracetic acid efficacy on disinfection of photostimulable phosphor plates.

Objectives: To evaluate the antimicrobial efficacy of white vinegar, acetic acid, and peracetic acid on photostimulable phosphor (PSP) plates disinfection, and to assess the disinfectant influence on the radiographic quality.

Methods: Eight PSP plates (Express system) were contaminated with Streptococcus mutans and Candida albicans. These plates were wiped with tissues without any substance, with white vinegar, acetic acid, and peracetic acid, followed by an agar imprint. Number of microbial colonies formed was recorded. Afterwards, the quality of radiographs was tested using the more efficient disinfectant. Before disinfection and after every five disinfections, two radiographs of an acrylic-block and two radiographs of an aluminium step-wedge were acquired for each plate. Density, noise, uniformity, and contrast were analysed. Three oral radiologists evaluated the images for the presence of artefacts. One-way analysis of variance compared changes on grey values among the disinfections (α = .05). Intra- and inter-examiner agreement for the presence of artefacts was calculated by weighted Kappa.

Results: Peracetic acid was the only one that eliminated both microorganisms. Density and uniformity decreased after 100 disinfections, and contrast changed without a pattern in the course of disinfections (P ≤ .05). Small artefacts were observed after 30 disinfections. Intra- and inter-examiner agreements were almost perfect.

Conclusions: Disinfection with peracetic acid eliminated both microorganisms. However, it also affected density, uniformity, and contrast of radiographs, and led to the formation of small artefacts.