陈旧性树脂表面形态对新旧树脂间粘结强度的影响

摘要

目的：研究陈旧性树脂表面形态学改变以及对新旧树脂间粘结强度的影响。方法：制备Z350纳米树脂样本10例，浸泡于37℃蒸馏水中1个月后，使用同种树脂完成样本制备，用体视显微镜和扫描电镜对样本的表面及切面进行形态学观察。万能材料试验机上测定材料的微拉伸强度。结果：陈旧性树脂表面纳米填料颗粒从树脂基质中消失，且新旧树脂间存在间隙，陈旧性树脂修复后微拉伸强度明显降低。结论：新旧树脂界面是导致树脂粘结强度下降的薄弱区。%　　Objective:To determine the change of morphology and micro-tensile strength between fresh and aged composite resin . Methods:After being stored in distilled water at 37℃for a month,ten specimens were used as substrate for the new Z 350 composite to adhere to.Specimens were then tested for the micro-tensile bond strength (μTBS) in a universal testing machine at a crosshead speed of 1 mm/min until failure.The surface and incisal surface morphology was analyzed using stereoscopic microscope and scanning electron microscope.Results:μTBS of aged composite resin was significantly lower than that of the fresh resin composite .The nano particles van-ished from the resin matrix on the surface of aged composite resin .A rough resin-resin interface appeared between fresh and aged com-posite resin.Conclusions:The surface of aged composite resin may affect the bond strength between fresh and aged composite resin .