疲劳循环对复合树脂微渗漏影响的体外研究

Microleakage of Resin-restoration after Chewing for Half a Year in Vitro

目的:通过体外加载实验观察复合树脂边缘微渗漏变化情况,分析洞缘斜面的必要性。方法:将140颗离体牙按是否制备洞缘斜面、不同疲劳循环加载次数及位点随机分为14小组。所有样本采用复合树脂(3M P60)充填,包埋后经不同疲劳循环次数(0、1×105、1.3×106次)或加载位点(颊尖、颊界面、修复体)进行加载试验,检测修复体界面染料渗透深度。结果:1.3×106次组微渗漏大于1×105次及0次组。0次加载时,不同洞缘组间差异不显著;加载1×105次后,牙体受力时洞缘斜面组的微渗漏比无洞缘斜面组小(P<0.05);加载1.3×106次后,洞缘斜面组微渗漏小于无洞缘斜面组(P<0.05)。结论:体外疲劳循环(模拟咀嚼半年)后,洞缘斜面有利于减少复合树脂的微渗漏。

Objective：To measure the microleakage of resin-restoration after chewing for half a year,and analyze the necessity of beveled margin using cyclic mechanical loading experiment.Methods：One hundred and forty fresh dissociated teeth were divided into 14 groups according to different cavity margin designs,different numbers of loading cycles（0or 1×105 times loading or 1.3×106 times loading cycles）,and different loading sites（the buccal cusp or the buccal interface or the restoration）.After all the cavities were filled with combined resins（3M FiltekTM P60）and entrapped,each sample received cyclic mechanical loading.Then all pieces were examined to observe the dye penetrated along the tooth-restoration interface.SPSS17.0software was used for statistical analysis.Results：The microleakage of 1.3×106 times loading group was larger than that of the 0and 1×105 times loading group.There was no significant difference among groups with beveled margin or not after 0cyclic loading（P〉0.05.After1.3×106 times loading,the microleakage of tooth loaded with beveled margin was less than that without beveled margin（P〈0.05）.Conclusion：After chewing for half a year,the beveled margin could reduce the microleakage of resin-restoration.