Long term durability of composite resin restorations in vivo and improvement

为了评价复合树脂修复体的长期耐久性，制备了颈洞，并按生产厂家的说明使用了各种粘结剂。定期观察这些填充物的临床表现。为了观察边缘适合性，对这些修复体进行了印记并制作了精确的复制品。用扫描电子显微镜观察这些复制品的形态。在许多情况下，早期的边缘适应是好的。18个月后观察边缘台阶。台阶的宽度随着时间的推移而延长。当粘结层暴露在边缘时，从暴露的粘结层开始磨损，树脂材料发生边缘断裂。釉质酸蚀有效地提高了釉质与牙釉质的适合性。

In order to evaluate the long term durability of composite resin restorations, cervical cavities were prepared Various bonding agents were applied according to the manufacturers' instructions. Clinical findings of these fillings were periodically observed. In order to observe the marginal adaptation, impressions of these restorations were taken and precision replicas were made. These replicas were observed by scanning electron microscope. In many cases, marginal adaptation of early stage was good. Marginal steps were observed after 18 months. The width of steps was extended with time. When the bonding layer was exposed at the margin, abrasion progressed from the exposed bonding layer and the marginal fracture of resin materials occurred. Enamel etching effectively improved the adaptation to enamel.