改性玻璃离子水门汀应力松弛蠕变实验

Stress relaxation and creep test of modified glass ionomer cement

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7200 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7200 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。

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.