Rodrigues Shobha, Suvarna Shivani, Suvarna Jyoti, Saralaya Vishwas, Saldanha Sharon, Shenoy Vidya K
Department of Prosthodontics, Manipal College of Dental Sciences, Mangalore, Manipal University, Karnataka, India.
Private Practitioner, Nair Hospital Dental College, Mumbai, Maharashtra, India.
Indian J Dent Res. 2017 Sep-Oct;28(5):555-559. doi: 10.4103/ijdr.IJDR_775_16.
Biofilms in dental unit waterlines (DUWLs), suction hoses, and fittings are a potentially significant source of cross-contamination posing significant health risk as these may come into contact with patients during treatment. The purpose of this in vitro study was to identify the spectrum of bacterial flora colonizing the DUWLs and to detect pathogenic microorganisms present in such an environmental niche.
Thirty DUWL samples were collected from in use dental units selected randomly from various clinical departments. Samples were collected from the following devices; 3-in-1 syringe waterline, section of waterline tubing supplying the 3-in-1 syringe, and the air rotor water. The samples were subjected to bacteriological analysis, and all bacterial isolates were tested for their ability to form biofilms.
A descriptive analysis of the results obtained was carried out, and it was observed that 7 out of 30 (23.3%) samples collected from DUWL were supplying water of unsatisfactory quality with species of low-pathogenicity bacteria isolated present in significant numbers; four of ten (40%) water supply lines contained bacterial biofilms; and the species with greatest capability to form biofilms were Enterobacter species (spp.). In addition, the results were also subjected to Chi-square test which revealed no statistical difference between the species and the location of collection of samples.
Within the limitations of this study, it is concluded that DUWLs are not totally free of contamination. Microbial biofilms are a significant source of cross-contamination and cross-infection in the dental clinic environment.
牙科设备水路（DUWLs）、吸引软管及配件中的生物膜是潜在的重大交叉污染源，在治疗过程中可能与患者接触，从而带来重大健康风险。本体外研究的目的是确定在DUWLs中定殖的细菌菌群谱，并检测存在于这种环境生态位中的致病微生物。
从各临床科室随机选取的在用牙科设备中收集30个DUWL样本。样本取自以下设备：三合一注射器水路、为三合一注射器供水的一段水管以及气涡轮水路。对样本进行细菌学分析，并对所有分离出的细菌进行生物膜形成能力测试。
对所得结果进行了描述性分析，观察到从DUWL收集的30个样本中有7个（23.3%）提供的水质不合格，分离出大量低致病性细菌种类；十条供水管路中有四条（40%）含有细菌生物膜；形成生物膜能力最强的菌种是肠杆菌属。此外，还对结果进行了卡方检验，结果显示样本的种类与采集位置之间无统计学差异。
在本研究的局限性范围内，得出结论：DUWLs并非完全无污染。微生物生物膜是牙科临床环境中交叉污染和交叉感染的重要来源。
