Raja Taiyub A, Littlewood Simon J, Munyombwe Theresa, Bubb Nigel L
a Specialist Orthodontist, St Luke's Hospital, Bradford, UK.
Angle Orthod. 2014 Jul;84(4):656-64. doi: 10.2319/061313-448.1. Epub 2013 Dec 23.
To investigate the resistance to wear of four different vacuum-formed retainer (VFR) materials: Essix C+, Essix ACE, Duran, and Tru-Tain. Essix C+ is a polypropylene polymer; the other materials are polyethylene co-polymers.
The study was undertaken at the Leeds Dental Institute, Leeds, UK, with 26 samples in each group. The specimens were vacuum-formed according to the manufacturers' guidelines, and a custom-made wear-simulation machine was used to conduct the test. Each specimen was subjected to 1000 cycles of the wear simulation, with steatite balls as the antagonist material. The resistance to wear of the VFR materials was evaluated by measuring the maximum wear depth using noncontact, three-dimensional surface profilometry. The wear depth was given in micrometers.
The median wear depth was 63.20 µm for the Essix C+ group, 7.88 µm for the Essix ACE group, 9.75 µm for the Duran group, and 12.08 µm for the Tru-Tain group. The Kruskal-Wallis test to compare the four VFR materials detected a statistically significant difference between the groups (P < .001). Comparisons of the groups using the Mann-Whitney U-test demonstrated that the Essix C+ group had significantly greater wear than the other three groups (P < .001). There was no statistically significant difference in median wear depth between the two groups with the least amount of wear-the Essix ACE and Duran groups.
Under the standardized conditions of this laboratory study, the three polyethylene co-polymer materials-Essix ACE, Duran, and Tru-Tain-exhibited significantly less wear than the polypropylene material, Essix C+.
研究四种不同的真空成型保持器（VFR）材料——Essix C+、Essix ACE、Duran和Tru-Tain的耐磨性。Essix C+是一种聚丙烯聚合物；其他材料是聚乙烯共聚物。
该研究在英国利兹的利兹牙科研究所进行，每组有26个样本。标本按照制造商的指南进行真空成型，并使用定制的磨损模拟机进行测试。每个标本进行1000次磨损模拟循环，以滑石球作为对抗材料。通过使用非接触式三维表面轮廓仪测量最大磨损深度来评估VFR材料的耐磨性。磨损深度以微米为单位给出。
Essix C+组的中位磨损深度为63.20 µm，Essix ACE组为7.88 µm，Duran组为9.75 µm，Tru-Tain组为12.08 µm。用于比较四种VFR材料的Kruskal-Wallis检验检测到各组之间存在统计学上的显著差异（P < .001）。使用Mann-Whitney U检验对各组进行比较表明，Essix C+组的磨损明显大于其他三组（P < .001）。磨损量最少的两组——Essix ACE组和Duran组——的中位磨损深度在统计学上没有显著差异。
在本实验室研究的标准化条件下，三种聚乙烯共聚物材料——Essix ACE、Duran和Tru-Tain——的磨损明显低于聚丙烯材料Essix C+。
