Nikaeen Mahnaz, Hatamzadeh Maryam, Sabzevari Zohre, Zareh Omolbanin
Department of Environmental Health Engineering, School of Public Health, Isfahan University of Medical Sciences, Isfahan, Iran.
J Res Med Sci. 2009 Sep;14(5):297-300.
Dental unit waterlines (DUWLs) are ideal environment for development of microbial biofilms. Microbial contamination of water in DUWLs is thought to be the result of biofilm formation as it could serves as a haven for pathogens. The aim of this study was to assess microbial quality of water in dental unit waterlines of dental units located at the dental school of Isfahan University of Medical Sciences.
Water samples were collected from air/water syringe and high-speed handpiece. Generally, 100-200 ml water samples were collected aseptically in sterile containers with sodium thiosulfate at the beginning of the day after a 2 minute purge. Samples were transferred to the laboratory in insulated box with cooling packs and examined for total viable heterotrophic bacteria and fungi.
The heterotrophic plate count levels were significantly exceeded the American Dental Association recommendations for DUWL water quality (< 200 CFU/ml), in both air/water syringe (84%, CFU/ml: 500-20000) and high-speed handpiece (96%, CFU/ml: 710-36800) samples. However, there was no significant difference between the level of contamination in the air/water syringe and high-speed handpiece. Fungi were found in 28% and 36% of air/water syringe and high-speed handpiece samples, respectively; and filamentous fungi were the most frequently isolated fungi.
DUWLs should be subjected to routine microbial monitoring and to a decontamination protocol in order to minimize the risk of exposure to potential pathogens from dental units.
牙科设备水线（DUWLs）是微生物生物膜生长的理想环境。DUWLs中的水受到微生物污染被认为是生物膜形成的结果，因为它可能成为病原体的庇护所。本研究的目的是评估位于伊斯法罕医科大学牙科学院的牙科设备的牙科设备水线中的水的微生物质量。
从空气/水注射器和高速手机中采集水样。通常，在每天开始时，经过2分钟冲洗后，用含有硫代硫酸钠的无菌容器无菌采集100 - 200毫升水样。样品用冷却包放在保温箱中转移到实验室，检测总活异养细菌和真菌。
空气/水注射器（84%，CFU/ml：500 - 20000）和高速手机（96%，CFU/ml：710 - 36800）样品中的异养平板计数水平均显著超过了美国牙科协会对DUWL水质的建议（< 200 CFU/ml）。然而，空气/水注射器和高速手机中的污染水平之间没有显著差异。分别在28%的空气/水注射器样品和36%的高速手机样品中发现了真菌；丝状真菌是最常分离出的真菌。
DUWLs应进行常规微生物监测并采用去污方案，以尽量减少接触牙科设备潜在病原体的风险。
