MacDonald David S, Waterfield J Douglas
University of British Columbia, Faculty of dentistry, Vancouver, British Columbia.
J Can Dent Assoc. 2011;77:b93.
The detectors (both solid-state sensors and photostimulable phosphor [PSP] plates) used for digital intraoral radiography cannot be autoclaved, and barriers are typically used to prevent the spread of infection. The aim of this study was to determine the effectiveness of a barrier envelope system for PSP plates.
Disinfected PSP plates were aseptically inserted into barrier envelopes and placed in a periapical location. One PSP plate was placed in each of 28 patients, and 12 plates in each of 2 volunteers (D.S.M., J.D.W.). After retrieval, each PSP plate was removed from its barrier envelope, immersed in trypticase soy broth and aliquots were plated on trypticase soy agar. Bacterial colonies were counted 2 days later.
Fifty-two PSP plates in barrier envelopes were evaluated for contamination. Quality assurance of the PSP plates before clinical placement revealed defects in the integrity of 4 barrier envelopes, caused by forceps-related damage or failure to achieve a uniform seal. These defects allowed substantial contamination. Contamination also occurred as a result of failure to extract the PSP plate from the barrier envelope cleanly. Of the 44 barriers with no obvious defects that were placed by either final-year dental students or a radiologist, only 3 allowed bacterial contamination of the PSP plate.
Detectors contained in barrier envelopes remain a potential source of contamination. PSP plates must be disinfected between removal from a contaminated barrier envelope and placement in a new barrier envelope. In addition, placement into the barrier envelope should ideally be carried out under aseptic conditions. Finally, the integrity of each sealed barrier envelope must be verified visually before release to the clinic.
用于数字口内放射摄影的探测器（固态传感器和光激励荧光板[PSP]）不能进行高压灭菌，通常使用屏障来防止感染传播。本研究的目的是确定PSP板屏障信封系统的有效性。
将消毒后的PSP板无菌插入屏障信封中，并放置在根尖部位。28名患者每人放置一块PSP板，2名志愿者（D.S.M.，J.D.W.）每人放置12块。取回后，将每块PSP板从其屏障信封中取出，浸入胰蛋白酶大豆肉汤中，并将等分试样接种在胰蛋白酶大豆琼脂上。2天后计数细菌菌落。
对52个装有屏障信封的PSP板进行了污染评估。临床放置前PSP板的质量保证显示，4个屏障信封的完整性存在缺陷，这是由镊子相关损坏或未能实现均匀密封造成的。这些缺陷导致了大量污染。未能将PSP板从屏障信封中干净地取出也导致了污染。在最后一年的牙科学生或放射科医生放置的44个无明显缺陷的屏障中，只有3个允许PSP板被细菌污染。
屏障信封中的探测器仍然是潜在的污染源。PSP板从受污染的屏障信封中取出并放入新的屏障信封之间必须进行消毒。此外，理想情况下应在无菌条件下将其放入屏障信封中。最后，在发放到临床之前，必须目视检查每个密封屏障信封的完整性。
