Neppelenbroek Karin Hermana, Pavarina Ana Cláudia, Spolidorio Denise Madalena Palomari, Vergani Carlos Eduardo, Mima Ewerton Garcia de Oliveira, Machado Ana Lúcia
Department of Dental Materials and Prosthodontics, São Paulo State University, Araraquara Dental School, São Paulo, Brazil.
Int J Prosthodont. 2003 Nov-Dec;16(6):616-20.
The aim of this study was to evaluate the effectiveness of microwave irradiation sterilization on hard chairside reline resins.
Specimens of three reline resins (Kooliner, Tokuso Rebase, and Ufi Gel Hard) were fabricated and subjected to ethylene oxide sterilization. The specimens were then individually inoculated (10(7) cfu/mL) with Tryptic Soy Broth media containing one of the tested microorganisms (C albicans, S aureus, B subtilis, and P aeruginosa). After 48 hours at 37 degrees C, the samples were vortexed for 1 minute and allowed to stand for 9 minutes, followed by a short vortex to resuspend any organisms present. After inoculation, 40 specimens of each material were immersed in 200 mL of water and subjected to microwave irradiation at 650 W for 6 minutes. Forty non-irradiated specimens were used as positive controls. Replicate specimens (25 microL) of suspension were plated at dilutions of 10(-3) to 10(-6) on plates of selective media appropriate for each organism. All plates were incubated at 37 degrees C for 48 hours. After incubation, colonies were counted, and the data were statistically analyzed by the Kruskal-Wallis test. Twelve specimens of each material were prepared for SEM.
All immersed specimens showed consistent sterilization of all the individual organisms after microwave irradiation. SEM examination indicated an alteration in cell morphology after microwave irradiation.
Microwave sterilization for 6 minutes at 650 W proved to be effective for the sterilization of hard chairside reline resins.
本研究旨在评估微波辐照灭菌对椅旁硬质重衬树脂的有效性。
制备三种重衬树脂（Kooliner、Tokuso Rebase和Ufi Gel Hard）的样本，并进行环氧乙烷灭菌。然后将样本分别接种（10⁷ cfu/mL）含有一种受试微生物（白色念珠菌、金黄色葡萄球菌、枯草芽孢杆菌和铜绿假单胞菌）的胰蛋白胨大豆肉汤培养基。在37℃下培养48小时后，将样本涡旋1分钟，静置9分钟，然后短暂涡旋以重新悬浮存在的任何微生物。接种后，将每种材料的40个样本浸入200 mL水中，并在650 W下进行6分钟的微波辐照。40个未辐照的样本用作阳性对照。将悬浮液的重复样本（25 μL）以10⁻³至10⁻⁶的稀释度接种在适合每种微生物的选择性培养基平板上。所有平板在37℃下培养48小时。培养后，计数菌落，并通过Kruskal-Wallis检验对数据进行统计分析。每种材料制备12个样本用于扫描电子显微镜（SEM）检查。
所有浸入的样本在微波辐照后对所有单个微生物均显示出一致的灭菌效果。SEM检查表明微波辐照后细胞形态发生了改变。
650 W下微波灭菌6分钟被证明对椅旁硬质重衬树脂的灭菌有效。
