Kang Young S, Rueggeberg Frederick, Ramos Van
Prosthodontic Mentor, U.S. Army Advanced Education Program in General Dentistry 2-year, Fort Bragg, NC.
Professor and Section Director, Dental Materials, Department of Oral Rehabilitation, Dental College of Georgia, Augusta University, Augusta, Ga.
J Prosthet Dent. 2017 Feb;117(2):266-270. doi: 10.1016/j.prosdent.2016.07.018. Epub 2016 Oct 17.
Polyvinyl siloxane (PVS) impression materials must be cold disinfected before cast pouring to prevent cross-contamination among personnel and patients. However, disinfection may affect the ability of PVS impression materials to provide bubble-free stone surfaces because of the removal of surfactants.
The purpose of this in vitro study was to compare the water contact angles of a PVS impression material treated with either a quaternary ammonium-based (QAB) (DisCide Ultra) or a chlorine-based (CLB) (Dispatch) disinfectant for various exposure times. No disinfection and acetone-immersed (total surfactant removal) specimens were used as positive and negative controls. An additional purpose was to measure changes in the contact angles of the disinfected PVS impression material after applying a topical wetting agent.
Flat and disk-shaped PVS specimens (n=5/test condition) were fabricated and subsequently exposed to disinfectants for different times (1 minute, 5 minutes, 30 minutes, 6 hours, and 24 hours). After disinfection, the contact angle with distilled water was determined over a 3-minute period using dynamic contact analysis. The same contact angle measurements were repeated after a wetting agent was applied to the previously disinfected specimens. Contact angles were statistically compared using 2-way ANOVA. The Sidak post hoc test was used to perform pairwise simple contrast and effect comparisons (α=.05).
The contact angle increased directly with disinfectant contact time. For the CLB product, the contact angle after 30-minute disinfection was not significantly different from that of 1 minute disinfection (P>.05). For the QAB product, exceeding 5-minutes of disinfection resulted in a significantly greater contact angle (P<.001). The application of a wetting agent made the disinfected PVS specimens less hydrophobic.
A QAB disinfectant product is more effective at removing surfactant than a CLB disinfectant product. Therefore, a CLB disinfectant provides more working time and control. A wetting agent can reduce the hydrophobicity of a disinfected impression material if the duration of cold disinfection is less than 6 hours.
在浇铸模型之前，必须对乙烯基聚硅氧烷（PVS）印模材料进行冷消毒，以防止在工作人员和患者之间发生交叉污染。然而，由于表面活性剂的去除，消毒可能会影响PVS印模材料提供无气泡石膏表面的能力。
本体外研究的目的是比较用季铵基（QAB）（DisCide Ultra）或氯基（CLB）（Dispatch）消毒剂处理不同暴露时间的PVS印模材料的水接触角。未消毒和丙酮浸泡（完全去除表面活性剂）的标本用作阳性和阴性对照。另一个目的是测量在应用局部湿润剂后消毒的PVS印模材料接触角的变化。
制作扁平圆盘状PVS标本（n = 5/测试条件），随后将其暴露于消毒剂中不同时间（1分钟、5分钟、30分钟、6小时和24小时）。消毒后，使用动态接触分析法在3分钟内测定与蒸馏水的接触角。在将湿润剂应用于先前消毒的标本后，重复相同的接触角测量。使用双向方差分析对接触角进行统计学比较。使用Sidak事后检验进行成对简单对比和效应比较（α = 0.05）。
接触角随消毒剂接触时间直接增加。对于CLB产品，30分钟消毒后的接触角与1分钟消毒后的接触角无显著差异（P>0.05）。对于QAB产品，超过5分钟的消毒导致接触角显著增大（P<0.001）。应用湿润剂使消毒后的PVS标本疏水性降低。
QAB消毒剂产品在去除表面活性剂方面比CLB消毒剂产品更有效。因此，CLB消毒剂提供更多的工作时间和控制。如果冷消毒时间少于6小时，湿润剂可以降低消毒后印模材料的疏水性。
