Effects of mechanical properties of thermoplastic materials on the initial force of thermoplastic appliances
Effects of mechanical properties of thermoplastic materials on the initial force of thermoplastic appliances
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DOI：
10.2319/052512-432.1
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发表时间：
2013-05-01
影响因子：
3.4
通讯作者：
Mizoguchi, Itaru
中科院分区：
文献类型：
--
作者：
Kohda, Naohisa;Iijima, Masahiro;Mizoguchi, Itaru
目的：为了测量由三种材料制成的热塑性矫治器提供的力，并研究机械性能、材料厚度和激活量对正畸力的影响，材料和方法：选择三种热塑性材料，Duran（Scheu Dental）、Erkodur（Erkodent Erich Kopp GmbH）和Hardcast（Scheu Dental），具有两种不同的厚度。弹性模量和硬度的值由28 ℃下的纳米压痕测量获得。一个定制的系统与力传感器被用来获得在体外力的测量提供的热塑性器具为0.5毫米和1.0毫米的激活身体牙齿移动。结果：Hardcast的弹性模量和硬度显著低于Duran和Erkodur，其性能没有显著差异。由较厚材料（0.75 mm或0.8 mm）制成的矫治器总是比由较薄材料（0.4 mm或0.5 mm）制成的矫治器产生更大的力。除了0.4 mm厚的Hardcast矫治器外，1.0 mm激活的矫治器产生的力显著低于0.5 mm激活的矫治器。一个很强的相关性被发现之间的机械性能的热塑性材料和力产生的appliance.Conclusions：正畸力提供的热塑性器具取决于材料，厚度和激活量。通过纳米压痕测试获得的聚合物的机械性能是这些器具的力传递的预测。（角度正交2013;83：476-483.）
Objective: To measure the forces delivered by thermoplastic appliances made from three materials and investigate effects of mechanical properties, material thickness, and amount of activation on orthodontic forces.Materials and Methods: Three thermoplastic materials, Duran (Scheu Dental), Erkodur (Erkodent Erich Kopp GmbH), and Hardcast (Scheu Dental), with two different thicknesses were selected. Values of elastic modulus and hardness were obtained from nanoindentation measurements at 28 degrees C. A custom-fabricated system with a force sensor was employed to obtain measurements of in vitro force delivered by the thermoplastic appliances for 0.5-mm and 1.0-mm activation for bodily tooth movement. Experimental results were subjected to several statistical analyses.Results: Hardcast had significantly lower elastic modulus and hardness than Duran and Erkodur, whose properties were not significantly different. Appliances fabricated from thicker material (0.75 mm or 0.8 mm) always produced significantly greater force than those fabricated from thinner material (0.4 mm or 0.5 mm). Appliances with 1.0-mm activation produced significantly lower force than those with 0.5-mm activation, except for 0.4-mm thick Hardcast appliances. A strong correlation was found between mechanical properties of the thermoplastic materials and force produced by the appliances.Conclusions: Orthodontic forces delivered by thermoplastic appliances depend on the material, thickness, and amount of activation. Mechanical properties of the polymers obtained by nanoindentation testing are predictive of force delivery by these appliances. (Angle Orthod. 2013;83:476-483.)