Silva Mariana Montenegro, Vergani Carlos Eduardo, Giampaolo Eunice Teresinha, Neppelenbroek Karin Hermana, Spolidorio Denise Madalena Palomari, Machado Ana Lúcia
Department of Dental Materials and Prosthodontics, Araraquara Dental School, São Paulo State University, Brazil.
Int J Prosthodont. 2006 May-Jun;19(3):288-93.
The purpose of this study was to evaluate the effectiveness of microwave irradiation on the disinfection of simulated complete dentures.
Eighty dentures were fabricated in a standardized procedure and subjected to ethylene oxide sterilization. The dentures were individually inoculated (10(7) cfu/mL) with tryptic soy broth (TSB) media containing one of the tested microorganisms (Candida albicans, Streptoccus aureus, Bacillus subtilis, and Pseudomonas aeruginosa). After 48 hours of incubation at 37 degrees C, 40 dentures were individually immersed in 200 mL of water and submitted to microwave irradiation at 650 W for 6 minutes. Forty nonirradiated dentures were used as positive controls. Replicate aliquots (25 microL) of suspensions 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. TSB beakers with the microwaved dentures were incubated at 37 degrees C for 7 more days. After incubation, the number of colony-forming units was counted and the data were statistically analyzed by Kruskal-Wallis test (alpha = .05).
No evidence of growth was observed at 48 hours for S. aureus, B. subtilis, and C. albicans. Dentures contaminated with P. aeruginosa showed small growth on 2 plates. After 7 days incubation at 37 degrees C, no growth was visible in the TSB beakers of S. aureus and C. albicans. Turbidity was observed in 3 broth beakers, 2 from P. aeruginosa and 1 from B. subtilis.
Microwave irradiation for 6 minutes at 650 W produced sterilization of complete dentures contaminated with S. aureus and C. albicans and disinfection of those contaminated with P. aeruginosa and B. subtilis.
本研究旨在评估微波辐射对模拟全口义齿消毒的有效性。
采用标准化程序制作80副义齿，并用环氧乙烷进行灭菌处理。将义齿分别接种（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（TSB）培养基。在37℃孵育48小时后，将40副义齿分别浸入200 mL水中，并在650 W功率下进行6分钟的微波辐射。40副未辐射的义齿用作阳性对照。将悬浮液的重复等分试样（25 μL）按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℃孵育48小时。装有经微波处理义齿的TSB烧杯在37℃再孵育7天。孵育后，计算菌落形成单位的数量，并通过Kruskal-Wallis检验（α = 0.05）对数据进行统计学分析。
在48小时时，未观察到金黄色葡萄球菌、枯草芽孢杆菌和白色念珠菌生长的迹象。被铜绿假单胞菌污染的义齿在2个平板上有少量生长。在37℃孵育7天后，金黄色葡萄球菌和白色念珠菌的TSB烧杯中未见生长。在3个肉汤烧杯中观察到浑浊，2个来自铜绿假单胞菌，1个来自枯草芽孢杆菌。
在650 W功率下进行6分钟的微波辐射可对被金黄色葡萄球菌和白色念珠菌污染的全口义齿进行灭菌，并对被铜绿假单胞菌和枯草芽孢杆菌污染的义齿进行消毒。
