改性玻璃离子水门汀应力松弛蠕变实验

文题释义：黏弹性力学：连续介质力学的重要分支，又称黏弹性理论，研究黏弹性物质的力学行为、本构关系及其破坏规律，以及黏弹性体在外力和其他因素作用下的变形和应力分布。聚合物、混凝土、金属、岩石、土壤、石油、肌肉、血液和骨骼等，在一定条件下既具有弹性性质又具有黏性性质，这种兼具弹性和黏性性质的材料称为黏弹性材料，含黏弹性固体与黏弹性流体，又可分为线性黏弹性体和非线性黏弹性体。线性黏弹性体的两种极端情况即为胡克体(遵循胡克定律)和牛顿流体(遵循牛顿粘性定律)。 生物力学：是应用力学原理和方法对生物体中的力学问题定量研究的生物物理学分支，其研究范围从生物整体到系统、器官(包括血液、体液、脏器、骨骼等)，从鸟飞、鱼游、鞭毛和纤毛运动到植物体液的输运等。 物力学的基础是能量守恒、动量定律、质量守恒三定律并加上描写物性的本构方程。生物力学研究的重点是与生理学、医学有关的力学问题，依研究对象的不同可分为生物流体力学、生物固体力学和运动生物力学等。 背景：以往对改性玻璃离子水门汀的力学性能研究多以压缩、弯曲实验居多，关于玻璃离子水门汀加入锶羟基磷灰石后的应力松弛、蠕变实验研究鲜有报道。 目的：对比分析传统玻璃离子水门汀、复合树脂釉质粘接剂、改性玻璃离子水门汀的应力松弛、蠕变特性。 方法：按质量比15%向玻璃离子水门汀中加入掺锶羟基磷灰石，制备改性玻璃离子水门汀。制作改性玻璃离子水门汀、复合树脂釉质粘接剂与传统玻璃离子水门汀试样，3组各取10个试样进行应力松弛实验，另取10个试样进行蠕变实验。 结果与结论：①应力松弛实验7 200 s时，传统玻璃离子水门汀组应力下降了1.18 MPa，复合树脂釉质粘接剂组应力下降了1.39 MPa，掺锶羟基磷灰石复合玻璃离子水门汀组应力下降了1.38 MPa；传统玻璃离子水门汀组应力下降量小于掺锶羟基磷灰石复合玻璃离子水门汀组、复合树脂釉质粘接剂组(P < 0.05)，掺锶羟基磷灰石复合玻璃离子水门汀组和复合树脂釉质粘接剂组应力下降量无差异(P > 0.05)。②蠕变实验7 200 s时，传统玻璃离子水门汀组应变上升了0.24%，复合树脂釉质粘接剂组应变上升了0.33%，掺锶羟基磷灰石复合玻璃离子水门汀组应变上升了0.32%；传统玻璃离子水门汀组应变上升量小于掺锶羟基磷灰石复合玻璃离子水门汀组、复合树脂釉质粘接剂组(P < 0.05)，掺锶羟基磷灰石复合玻璃离子水门汀组试和复合树脂釉质粘接剂组应变上升量无差异(P > 0.05)。③结果表明，15%掺锶羟基磷灰石提高和改善了玻璃离子水门汀的黏弹特性，有利于其与黏结物体的黏结，有利于提高黏结强度。 ORCID: 0000-0003-1024-5733(丁洁) 中国组织工程研究杂志出版内容重点：生物材料；骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性；组织工程

Stress relaxation and creep test of modified glass ionomer cement

BACKGROUND:Most of studies on the mechanical properties of modified glass ionomer cement mainly focus on the compression and bending experiments,but there are few reports on the stress relaxation and creep experiments of glass ionomer cement after adding strontium hydroxyapatite.OBJECTIVE:To compare the stress relaxation and creep characteristics of traditional glass ionomer cement,composite resin enamel adhesive and modified glass ionomer cement.METHODS:Strontium doped hydroxyapatite was added into glass ionomer cement according to the mass ratio of 15%,and then the modified glass ionomer cement was prepared.Samples of modified glass ionomer cement,composite resin enamel adhesive and traditional glass ionomer cement were maded.Ten samples from each group were taken for stress relaxation test and another 10 samples for creep test.RESULTS AND CONCLUSION:(1)At 7200 s in the stress relaxation test,the stress in the traditional group was decreased by 1.18 MPa,decreased by 1.39 MPa in the composite group,and decreased by 1.38 MPa in the modified group.The decreased value in the traditional group was significantly less than that in the composite and modified groups(P<0.05).There was no significant difference between composite and modified groups(P>0.05).(2)At 7200 s in the creep test,the stress in the traditional group was increased by 0.24%,increased by 0.33%in the composite group,and increased by 0.32%in the modified group.The increased value in the traditional group was significantly less than that in the composite and modified groups(P<0.05).There was no significant difference between composite and modified groups(P>0.05).(3)The viscoelastic properties of glass ionomer cement are improved by compounding 15%strontium-doped hydroxyapatite with glass ionomer cement.The increase of viscoelasticity is beneficial to the adhesion and bulk bond strength of glass ionomer cement.