摘要
背景:已证实不同聚合方式聚甲基丙烯酸甲酯的力学性能不同,且不同种类的聚甲基丙烯酸甲酯的力学性能也存在差异。目的:探讨不同混合比例聚甲基丙烯酸甲酯的力学性能差异。设计、时间及地点:材料学对比观察,于2009-02/05在天津医科大学总医院骨科生物力学实验室完成。材料:义齿基托树脂Ⅱ型自凝牙托粉由上海珊瑚化工厂生产,义齿基托树脂自凝牙托水由天津市口腔医院材料研究室生产。方法:在室温25℃环境下,将自凝牙托粉与牙托水分别按质量体积比1.5:1,1:1,1:1.25,1:1.5,1:1.75,1:2这6种不同混合比例调和,调配时搅拌速率为60次/min。当牙托水基本与牙托粉结合,无多余牙托水存在,黏着感消失时,即为填塞型盒最适宜时期,此时将混合材料充入直径13mm、长度100mm的模具中,分别制作出外形相同的聚甲基丙烯酸甲酯试件,对其进行压缩、拉伸和三点弯实验,直至屈服或破裂。主要观察指标:同混合比例聚甲基丙烯酸甲酯的抗压强度、抗拉强度、挠度和弹性模量。结果:①牙托粉与牙托水比例1.5:1,1:1组的抗压强度无明显差异(P=0.326),但均显著高于后4组(P<0.01);后3组的抗压强度无明显差异(P>0.05)。②牙托粉与牙托水比例1.5:1,1:1,1:1.25组的抗拉强度无明显差异(P>0.05),但均显著高于后3组(P<0.01)。后3组的抗拉强度无明显差异(P>0.05)。③随着牙托粉与牙托水的比例越来越小,其挠度值逐渐增大,说明韧性越来越好。④从前5组来看,随着牙托粉与牙托水的比例越来越小,其弹性模量值逐渐缩小,说明试件的刚性越来越差(P<0.01)。结论:聚甲基丙烯酸甲酯具有较高的强度和刚度,不同混合比例聚甲基丙烯酸甲酯的力学性能有明显差异。随着牙托粉与牙托水的混合比例逐渐缩小,聚合后液态单体的剩余量就越多,其抗压强度、抗拉强度和弹性模量值就越小。
BACKGROUND： Studies have been proved that different polymerization of poly methyl methacrylate （PMMA） has different mechanical properties, the mechanical properties in different types of PMMA is also different. OBJECTIVE： To explore mechanical property difference in the different mixing ratio of PMMA. DESIGN, TIME AND SETTING： The comparative observation was performed at the laboratory of Orthopaedic Biomechanics, General Hospital of Tianjin Medical University from February to May 2009. MATERIALS： Denture bases self-curing denture acrylics were made in Shanghai Coral Chemical Plant and Denture bases liquid for denture acrylics were made in Tianjin Stomatological Hospital Material Research Laboratory. METHODS： We mixed self-curing denture acrylic and liquid for denture acrylic at 1.5： 1, 1： 1, 1： 1.25, 1： 1.5, 1： 1.75 and 1： 2 six different kinds of hybrid scale at 25 ℃, at a speed rate of 60 times/min. When dental base acrylic resin liquid was combined with dental base acrylic resin powder, no extra dental base acrylic resin liquid was found. When adhesion feeling disappeared, it was the suitable stage of packing box. The mixed material was filled in a tooting （13 mm diameter, 100 mm length）. The same shape specimen of PMMA was established, and then the compression test, tension test, and three-point compression test until to yield or fracture were conducted. MAIN OUTCOME MEASURES： The compressive strength, tensile strength, deflection and elastic modulus of different mixing ratio of PMMA were measured. RESULTS： The compressive strength in the first two groups did not show significant differences （P=0.326）, and was significantly greater than other groups （P 〈 0.01）, but there were no significant differences in compressive strength in last three groups （P 〉 0.05）. The difference of tensile strength among the first three groups was not significant （P 〉 0.05）, but significantly greater than in the last three groups （P 〈 0.01）. The difference was not significant among the later three groups （P 〉 0.05）. With the mixing ratio getting smaller, the deflection was increased, which showed toughness getting better. With the mixing ratio getting smaller, the elastic modulus was getting smaller in the first five groups, which showed rigidity of specimen getting worse （P 〈 0.01）. CONCLUSION： PMMA has high strength and rigidity, and there are significant differences in mechanical property of PMMA at various mixed ratio. With the mixing ratio getting smaller, the residual amount of liquid monomer is more after polymerization, so the compressive strength, tensile strength and elastic modulus is smaller.
出处
《中国组织工程研究与临床康复》
CAS
CSCD
北大核心
2009年第42期8307-8310,共4页
Journal of Clinical Rehabilitative Tissue Engineering Research
基金
天津市自然科学基金资助项目(043111411
993607711)~~
