摘要：Objective:To evaluate the effectiveness of the sealing ability of 3 cements used on vertically fractured molars in vitro,and to observe the microleakage of the different cements and dentin.Methods:Sixty human molars were randomly divided into two groups:freshly vertically fractured group with closed crack and dated vertically fractured group with 2mm crack on occlusal surfaces.Then,the models were bonded with glass ionomer cement,Unicem or Super-Bond C&B (n=10).After concretion of 3 cements,the teeth were prepared for full-crown.Resin crowns were fabricated and bonded with glass ionomer cement on teeth.After immersed in water at 37℃ for 7 days,specimens were subjected to 500 thermocycling ranging between 4℃ and 55℃.Then,they were placed into a 0.5％ basic fuchsin dye for 7d.After soaking,fissure sealing degree and microleakage depth were observed using dental microscope.All statistical analysis was performed using SPSS 17.0 software package.Results:In the freshly vertically fractured group,Super-Bond C&B was effective in the sealing of the crack,while glass ionomer cement and Unicem could not seal the crack.The mean dye penetration length of models were l.28± 0.43mm,2.36± 0.35mm and 3.64± 0.95mm,respectively.And there were significant differences among 3 cements(P＜ 0.05).In the dated vertically fractured group,Super-Bond C&B was effective in the sealing of the root,glass ionomer cement and Unicem could not seal root completely.The mean dye penetration length of models were 2.15± 0.40mm、3.13± 0.81 mm and 3.85± 0.70mm,respectively.And there were significant differences among 3 cements(P＜0.05).Conclusions:This study showed that Super-Bond C&B used as bonded sealing material for vertically fractured teeth was better than glass ionomer cement and Unicem in the microleakage and fluidity.%目的:评价纵裂磨牙应用3种水门汀进行粘接内固定的实验效果,并观察裂隙内的微渗漏情况.方法:选用人离体磨牙60颗,随机分为新鲜纵裂组和陈旧纵裂组,分别为裂隙密合和(牙合)面裂隙保持2mm间隙.后将两组牙齿分别以玻璃离子、自粘接树脂水门汀Unicem和超级粘接剂粘接纵裂的裂隙(n=10),待材料凝固后行全冠牙体预备,观察预备体是否会复裂,并以树脂冠修复.全部试件置入37℃生理盐水中7d,并4℃-55℃冷热循环500次后,放置于0.5％的品红溶液中染色7d,观察裂隙封闭程度并在根管显微镜下观察微渗漏情况,采用SPSS 17.0软件包对数据进行统计学处理.结果:新鲜纵裂组中,牙体预备后均未复裂,超级粘接剂能完全封闭裂隙,Unicem和玻璃离子均不能渗入裂隙,染料渗入长度分别为(1.28±0.43)mm、(2.36±0.35)mm和(3.64±0.95)mm,三组间差异有统计学意义(P＜0.05)；陈旧纵裂组中,牙体预备后均未复裂,超级粘接剂能完全封闭裂隙,Unicem和玻璃离子均不能渗入到根尖,染料渗入长度分别为(2.15±0.40)mm、(3.13±0.81)mm和(3.85±0.70)mm,三组间差异有有统计学意义(p＜0.05).结论:相对于玻璃离子和树脂水门汀Unicem,超级粘接剂在粘接固定纵裂磨牙时的流动渗入能力较好,边缘微渗漏较少.
