Queen Mary University of London, London, E1 4NS, UK.
Centre Lead for Oral Bioengineering, Queen Mary University of London, Mile End Road, London, E1 4NS, UK.
Clin Oral Investig. 2024 Mar 2;28(3):185. doi: 10.1007/s00784-024-05503-x.
To compare four commercially available Essix-type retainers in terms of longevity, wear characteristics, stiffness and their range of rigidity.
An in vitro study was conducted at Queen Mary University of London. Four groups of thermoplastic materials were included: Duran (PETG), Essix C + (Polypropylene), Vivera and Zendura (Polyurethane). A working typodont was fabricated to evaluate surface wear characteristics using a wear machine with a customized jig. Retainers were measured for tensile test, and water absorption was measured at five different time points up to 6 months after initial immersion in two different physical states and two different solutions. Hydrolytic degradation was also evaluated using FTIR spectroscopy.
Essix C + was the most flexible retainer with Vivera the stiffest material. Zendura and Essix C + had the most surface wear (413 μm ± 80 and 652 μm ± 12, respectively) with absorption rates of up to 15 wt% in artificial saliva occurring with Zendura. Only Essix C + displayed signs of degradation following water absorption.
All materials had characteristic levels of flexibility and were susceptible to water absorption. Duran 1.5 mm performed similarly to Vivera in relation to stiffness and wear properties. While Zendura and Vivera have similar chemical structures, they exhibited differences concerning wear resistance and water absorption. Further clinical research evaluating the clinical relevance of these laboratory findings is required.
Characteristic patterns of wear and rigidity of four commercially available Essix-type retainers were observed. This information should help in the tailoring of retainer material on a case-by-case basis considering treatment-related factors and patient characteristics including parafunctional habits.
比较四种市售的 Essix 型保持器在耐用性、磨损特性、刚性和弹性范围方面的差异。
该体外研究在伦敦玛丽女王大学进行。共纳入四组热塑性材料：Duran（PETG）、Essix C+（聚丙烯）、Vivera 和 Zendura（聚氨酯）。使用带有定制夹具的磨损机在工作型牙合架上评估表面磨损特性。对保持器进行拉伸试验，并在初始浸入两种不同物理状态和两种不同溶液后的 5 个不同时间点测量水吸收。还使用傅里叶变换红外光谱法评估水解降解。
Essix C+是最柔软的保持器，而 Vivera 是最硬的材料。Zendura 和 Essix C+的表面磨损最多（分别为 413μm±80 和 652μm±12），在人工唾液中 Zendura 的吸水率高达 15wt%。只有 Essix C+在吸水后显示出降解迹象。
所有材料都具有一定程度的柔韧性，且易吸水。Duran 1.5mm 在刚度和磨损性能方面与 Vivera 相似。虽然 Zendura 和 Vivera 具有相似的化学结构，但它们在耐磨性和吸水性方面表现出差异。需要进一步进行评估这些实验室发现的临床相关性的临床研究。
观察到四种市售的 Essix 型保持器的磨损和刚性的特征模式。这些信息应有助于根据治疗相关因素和患者特征（包括功能习惯）在个案基础上定制保持器材料。
