Porteous N, Dang S, Schoolfield J, Sun Y
Department of Comprehensive Dentistry, The University of Texas Health Science Center at San Antonio, San Antonio, TX, USA.
Department of Chemistry, The University of Massachusetts, Lowell, MA, USA.
J Clin Dent. 2016 Mar;27(1):19-22.
The objective of this study was to test the biofilm-controlling properties of N-halamine antimicrobial dental unit waterline (DUWL) tubing (T) tubing, without recharging over one year, compared to a control line (C).
A simulated clinical model was used to pump ultrapure water through T and C lines at a rate of 1.4 mL/min, five minutes on, 15 minutes off, eight hours/day, five days a week. Samples of source water, effluent from T and C, and from the stagnant water in the carboy (liquid container) after bench work was completed (S2), were collected aseptically, serially diluted, and cultured on R2A agar for seven days every six weeks. SEM images of the inside surfaces of detached tubing sections were also taken. The carboy was rinsed with a 1:10 dilution of sodium hypochlorite after six months. Means of log transformed CFU values obtained in triplicate were paired by T and C lines across months for comparison by paired Student's t-tests.
An increase in effluent and carboy bacterial counts were noted after six months, but decreased after bleach rinse of the carboy. No significant difference (p > 0.25) between T and C lines were observed; similarly, T and carboy were not significantly different (p > 0.30). SEM images showed biofilm attachment on the inside surface of C after two months, but not on T. Organisms identified in the effluent reflected those in the source carboy.
No biofilm attachment was detected on the N-halamine test line after 12 months, indicating its antimicrobial properties were retained. Further evaluation is recommended to determine the optimal recharge interval for N-halamine DUWL tubing when ultrapure source water is used.
本研究的目的是测试与对照管线（C）相比，无需一年以上再充电的N-卤胺抗菌牙科单元水线（DUWL）管材（T）管材的生物膜控制特性。
使用模拟临床模型，以1.4 mL/分钟的速率将超纯水通过T和C管线泵送，开5分钟，关15分钟，每天8小时，每周5天。在每六周的无菌条件下收集原水、T和C的流出物以及实验台工作完成后大玻璃瓶（液体容器）中死水的样品（S2），进行系列稀释，并在R2A琼脂上培养7天。还拍摄了分离的管材段内表面的扫描电子显微镜（SEM）图像。六个月后，用1:10稀释的次氯酸钠冲洗大玻璃瓶。将一式三份获得的对数转换后的CFU值的平均值按T和C管线按月配对，通过配对学生t检验进行比较。
六个月后观察到流出物和大玻璃瓶细菌计数增加，但在大玻璃瓶用漂白剂冲洗后减少。T和C管线之间未观察到显著差异（p>0.25）；同样，T和大玻璃瓶也没有显著差异（p>0.30）。SEM图像显示两个月后C的内表面有生物膜附着，而T上没有。流出物中鉴定出的微生物反映了源大玻璃瓶中的微生物。
12个月后在N-卤胺测试管线上未检测到生物膜附着，表明其抗菌性能得以保留。建议进一步评估以确定使用超纯源水时N-卤胺DUWL管材的最佳再充电间隔。
