中文摘要：

目的比较Clearfil S3 Bond和Single Bond,Clearfil SE Bond,XenoⅢBond,G Bond对L929细胞活力的影响。方法小鼠成纤维细胞L929在Clearfil S3 Bond,Single Bond,Clearfil SE Bond,XenoⅢBond,G-Bond五种牙本质粘结剂的不同体积分数浸渍液（100%、50%、25%、12.5%）作用不同时间（24 h、72 h、120 h）后,倒置相差显微镜观察细胞形态变化,MTT法测定细胞相对增值率（RGR）;用5级毒性分类法评级,并进行统计分析。结果 5种牙本质粘结剂在不同体积分数浸渍液的作用下,L929细胞形态均发生不同程度的变化。在72 h、120 h后,12.5%Clearfil S3 bond组和Clearfil SE Bond组的RGR值显著高于其它各组的RGR值（P〈0.05）。结论 5种牙本质粘结剂的体外细胞毒性均较弱,其中第7代牙本质粘结剂Clearfil S3Bond和第5代牙本质粘结剂Clearfil SE Bond的细胞毒性显著低于其他几种粘结剂,可以安全地应用于临床。

英文摘要：

Objective To compare cytotoxicity of Clearfil S3 Bond and other four dentin adhesives to L929 cell with the method of MTT. Methods L929 mouse fibroblasts were exposed to different concentrations（ 12. 5%,25%,50% and 100%） of Clearfil S3 Bond,Single Bond,Clearfil SE Bond,Xeno Ⅲ Bond,G-Bond for different time（ 24 h,72 h and 120 h）. The relative proliferation rate of L929 mouse fibroblasts was calculated,and the toxicity was measured and ranked as 5 grades. The data were statistically analyzed. Results After 72 h,120 h,cytotoxicity of 12. 5% Clearfil S3 Bond and 12. 5% Clearfil SE Bond was less than that of other three dentin adhesives. The difference was statistically significant（ P〈0. 05）. Conclusions All these five kinds of dentin adhesives have weak cytotoxicity. Among them,the cytotoxicity of Clearfil S3 Bond and that of Clearfil SE Bond are the least,so they could be applied in clinic safely.