School of Dentistry, The University of Queensland, Herston, Qld, Australia.
Int J Paediatr Dent. 2022 May;32(3):401-408. doi: 10.1111/ipd.12919. Epub 2021 Oct 24.
Preformed crowns (PCs) are exposed to potentially infectious bodily fluids during the trial fit; however, whether they can be safely re-used remains uncertain. This study determined the effects of decontamination methods on various PCs. The key criteria examined were aesthetic, morphological, and elemental characteristics.
This is a laboratory-based experimental study. Stainless steel, pre-veneered stainless steel, and zirconia PCs underwent either: (a) ultrasonic cleaning with EmPower followed by steam sterilisation, (b) thermal disinfection in an instrument washer with Asepti Neutraliser/Asepti followed by steam sterilisation, or (c) immersion in an ortho-phthalaldehyde (OPA) instrument-level disinfectant. The methods were performed for 1, 5, or 10 cycles, and scanning electron microscopy (SEM); red, green, and blue (RGB) value; and luminosity value were tracked (using a histogram of individual colour reference chips in Adobe Photoshop ) to assess colour changes, and energy-dispersive X-ray (EDX) spectroscopy to characterise the material composition.
Pre-veneered stainless steel crowns showed isolated zones of darkening with loss of luminosity and variations in green and blue values after ultrasonic or thermal washer disinfection combined with steam autoclaving at 5 and 10 cycles. No changes occurred with OPA. Both SEM imaging and EDX analysis identified no changes to crown materials from any of the three reprocessing methods.
Reprocessing protocols need to reflect the differing responses of various types of PCs. Repeated steam sterilisation causes slight aesthetic alterations by way of colour instability and loss of luminosity to pre-veneered stainless steel crowns, but no issues with stainless steel or zirconia PCs.
预成冠（PCs）在试戴过程中会接触到潜在的传染性体液；然而，它们是否可以安全重复使用仍不确定。本研究旨在确定不同消毒方法对各种 PCs 的影响。主要检查的标准是美学、形态和元素特征。
这是一项基于实验室的实验研究。不锈钢、预贴面不锈钢和氧化锆 PCs 分别经历以下处理：（a）用 EmPower 进行超声清洗，然后蒸汽灭菌，（b）在带有 Asepti Neutraliser/Asepti 的器械清洗器中进行热消毒，然后蒸汽灭菌，或（c）浸泡在邻苯二甲醛（OPA）器械级消毒剂中。处理方法进行 1、5 或 10 个循环，并用扫描电子显微镜（SEM）、红、绿、蓝（RGB）值和亮度值（使用 Adobe Photoshop 中单个颜色参考芯片的直方图）进行跟踪，以评估颜色变化，并进行能量色散 X 射线（EDX）光谱分析以表征材料组成。
预贴面不锈钢冠在经过超声或热清洗器消毒与蒸汽高压灭菌联合处理 5 和 10 个循环后，出现孤立的变暗区域，亮度降低，绿色和蓝色值发生变化。OPA 则无变化。SEM 成像和 EDX 分析均未发现三种再处理方法对冠材料有任何变化。
再处理方案需要反映各种类型的 PCs 的不同反应。重复蒸汽灭菌会导致预贴面不锈钢冠出现轻微的美学变化，表现为颜色不稳定和亮度丧失，但对不锈钢或氧化锆冠无影响。
