Department of Chemical Engineering, National Technical University of Athens, Zografou Campus, Hroon Polytexneiou 9, 15780 Athens, Greece.
Dent Mater. 2009 Dec;25(12):1493-502. doi: 10.1016/j.dental.2009.06.018. Epub 2009 Aug 14.
The degradation of maxillofacial prosthetic elastomers that occurs during physical weathering is usually responsible for the replacement of prostheses. In this study the mechanical behavior of 4 non-pigmented facial prosthetic elastomers, exposed to outdoor weathering for 1 year, was investigated. The hypothesis investigated was that irradiation time did not affect the properties measured.
The samples were exposed to solar radiation for 1 year in Thessaloniki (Greece). Three different types of polydimethyl siloxane (PDMS) and chlorinated polyethylene (CPE) samples were tested in this study. Mechanical tests (compressive-tensile) were performed using a universal type testing machine. Hardness tests were evaluated using a durometer tester. Simple mathematical models were developed to correlate the measured properties with irradiation time. The stress-strain data of compression and tensile tests were modeled using parameters such as maximum stress (sigma(max)), maximum strain (epsilon(max)), elasticity parameter (E), and non-linearity parameter (p), while the mathematical model used for hardness data involves initial hardness of materials (H(0)).
Two of the silicone prosthetics (Elastomer 42, TechSil 25) seem to become harder and more brittle contrary to the other silicone (M 511) and chlorinated polyethylene (CPE) samples that become softer and more ductile. Duration of exposure increases these phenomena.
The effect of irradiation time on the mechanical behavior was introduced through its effect on the models' parameters. The hypothesis was rejected since changes were observed in the model parameters.
在物理风化过程中发生的颌面修复弹性体的降解通常是导致修复体更换的原因。本研究调查了 4 种非着色面部修复弹性体在户外风化 1 年后的机械性能。研究的假设是辐照时间不会影响测量的性能。
将样品在希腊塞萨洛尼基暴露于太阳辐射 1 年。本研究测试了三种不同类型的聚二甲基硅氧烷（PDMS）和氯化聚乙烯（CPE）样品。使用万能试验机进行机械测试（压缩-拉伸）。使用硬度计评估硬度测试。开发了简单的数学模型，将测量的性能与辐照时间相关联。使用参数（最大应力（sigma(max)）、最大应变（epsilon(max)）、弹性参数（E）和非线性参数（p））对压缩和拉伸测试的应力-应变数据进行建模，而用于硬度数据的数学模型涉及材料的初始硬度（H(0)）。
两种硅树脂修复体（Elastomer 42，TechSil 25）似乎变得更硬更脆，而另一种硅树脂（M 511）和氯化聚乙烯（CPE）样品则变得更软更韧。暴露时间的延长会加剧这些现象。
通过其对模型参数的影响，引入了辐照时间对机械行为的影响。由于模型参数发生了变化，因此假设被拒绝。
