Beatty M W, Swartz M L, Moore B K, Phillips R W, Roberts T A
Department of Adult Restorative Dentistry, UNMC College of Dentistry, Lincoln, Nebraska 68583-0740.
J Biomed Mater Res. 1993 Mar;27(3):403-13. doi: 10.1002/jbm.820270314.
Seven mechanical/physical properties were used to evaluate 10 unfilled resins: eight aromatic dimethacrylates and two urethane dimethacrylates. Physical property tests included compressive strength, Young's modulus in compression, uniaxial tensile strength, intrinsic yield point, toothbrush abrasion, Knoop hardness, and water sorption. Controlled changes were made in the following four material parameters: amount of crosslinking diluent present in the uncured monomer, functionality of the monomer, repeat unit chemistry of the monomer (urethane vs. aromatic structure) and mode of activation (chemical vs. visible light). Polymers containing a high concentration of crosslinking agent (50 wt%) were found to be tougher and to possess lower hardness than materials containing lesser amounts of crosslinking agent. This was attributed to the flexible nature of the triethylene glycol dimethacrylate crosslinking molecule. Exposure to water plasticized the highly crosslinked materials to the degree that the yield point and elastic modulus were effectively lowered. Most of the tested properties were unaffected by differences in functionality except resistance to toothbrush abrasion, which was enhanced for polymers derived from high functionality monomers. The urethane-based polymers sorbed substantially more water than the aromatic-based materials, which presumably resulted in lower values for surface hardness. However, the urethane resins were very tough, and excellent resistance to toothbrush abrasion was observed. Property differences caused by differences in activation mode were small, although the visible light materials did sorb more water.
使用七种机械/物理性能来评估10种未填充树脂：8种芳香族二甲基丙烯酸酯和2种聚氨酯二甲基丙烯酸酯。物理性能测试包括抗压强度、压缩杨氏模量、单轴拉伸强度、固有屈服点、牙刷磨损、努氏硬度和吸水率。对以下四个材料参数进行了可控变化：未固化单体中交联稀释剂的含量、单体的官能度、单体的重复单元化学结构（聚氨酯与芳香族结构）以及活化方式（化学活化与可见光活化）。发现含有高浓度交联剂（50 wt%）的聚合物比含有较少量交联剂的材料更坚韧且硬度更低。这归因于三乙二醇二甲基丙烯酸酯交联分子的柔性本质。暴露于水中会使高度交联的材料发生增塑，以至于屈服点和弹性模量有效降低。除了对牙刷磨损的抗性外，大多数测试性能不受官能度差异的影响，对于源自高官能度单体的聚合物，其对牙刷磨损的抗性增强。聚氨酯基聚合物比芳香族基材料吸收的水分要多得多，这可能导致表面硬度值较低。然而，聚氨酯树脂非常坚韧，并且观察到其对牙刷磨损具有优异的抗性。尽管可见光固化材料确实吸收了更多水分，但由活化方式差异引起的性能差异很小。
