Studyo of Micro leakage of Tunnel Cavity Preparation and Filling Method

研究了边缘渗漏隧道洞的制备和充填方法。在窝洞制备中，改进超声洁牙机，用于去除难处理部位的软质牙本质。对连接到洁牙器上的匙形exca和2号圆形布尔斯钻头进行了测试，发现2号圆形钻头更易于使用。充填方法中，增量法的边缘渗漏优于整体法，而grass离子水门汀和复合树脂增量法的边缘渗漏与复合树脂增量法的边缘渗漏相当，但更稳定。当这个隧道洞是在实验室准备四年级学生班，98名学生中有两个边缘脊缺陷。隧道洞是一种安全的洞型制备方法，手术干预少，值得临床推广应用。

Marginal leakage of Tunnnel cavity preparation and filling method were studied. In cavity preparation, Ultra sonic scaler was improved and used to remove soft dentin located at difficult places for treatment. Attached to the scaler, spoon exca types and #2 round burs were tested and #2 round bur was found to be easier to use. In filling method, marginal leakage of incremental filling methods were excellent than that of bulk methods, and the results of incremental methods of grass ionomer cement and composite resin were as good as those of incremental methods of composite resins but were more stable. When this tunnnel cavity was prepared in the laboratory class for the 4th graders, two out of 98 students had marginal ridge defect. As being demonstrated, the tunnel cavity is safe cavity preparation, with minimal intervention, so that it should bemore widely used in clinic.