5种牙本质粘结系统粘结强度的比较

目的用微拉伸粘结强度检测法评价5种不同类型的牙本质粘结系统与正常牙本质的粘结强度,用体视显微镜分析其断裂类型。方法选择25颗正畸治疗拔除的健康前磨牙,去除面釉质层,随机均分为5组。选用5种牙本质粘结系统:传统三步法全酸蚀粘结系统All-Bond2组、两步法全酸蚀粘结系统Prime&BondNT组、两步法自酸蚀粘结系统Fluoro-Bond组、一步法自酸蚀粘结系统XenoⅢ组和一步法自酸蚀粘结系统iBond组,分别用于暴露的表层牙本质面上,再用蓝色复合树脂恢复牙冠至要求高度。用低速锯将牙齿片切为横截面积约0.81mm2的长方体状样本,用微拉伸测试仪检测其粘结强度,加载速度为1mm/min。用体视显微镜观察样本断端形态。用SPSS11.5对微拉伸粘结强度测试值进行统计学分析。结果5种牙本质粘结系统的微拉伸粘结强度分别为All-Bond2组(28.74±5.15)MPa,Prime&BondNT组(25.85±3.37)MPa、Fluoro-Bond组(20.60±2.96)MPa、Xeno组(22.93±3.97)MPa、iBond组(25.67±4.72)MPa。All-Bond2组的微拉伸粘结强度与Prime&BondNT组测值之间差异无显著性,高于Fluoro-Bond组、Xeno组和iBond组,后两者的测值间差异无显著性,Fluoro-Bond组和Xeno组亦无显著差异。体视显微镜观察结果显示,绝大部分样本的断裂类型都是粘结面型断裂。结论5种牙本质粘结系统与正常牙本质的粘结强度存在差异,All-Bond2的粘结强度最高,但临床操作复杂,技术要求较高;XenoⅢ、iBond使用方法较简单,对牙髓的影响可能较小。

Microtensile bond strengths of five dentin adhesive systems

Objective To evaluate in vitro the microtensile bond strengths of five dentin adhesive systems and their respective fracture modes.Methods A total of 25 intact young human premolars extracted for orthodontic reasons were used.The enamel of occlusal surfaces of these premolar teeth was removed and superficial dentine was exposed,finished with wet 600-grit silicon carbide paper.And then these teeth were randomly divided into five groups.A block of composite resin was bonded respectively with five dentin adhesive systems ： All-bond 2 （ Group AB2 ） , Prime ＆ Bond NT （ Group PB ）, Fluoro-Bond （ Group FB ） , Xeno Ⅲ（ Group Xeno） and iBond （Group iBond） according to manufacturers＇instructions. The bonded teeth were kept in distilled water for 24h at 37℃. The roots were removed from the remaining crown approximately i-2 mm below the cemento-enamel junction with a slow-speed diamond saw. The teeth were sectioned to obtain bar-shaped specimens ,whose bonded surface areas were about 0. 81 mm2 . The specimens were stressed at a crosshead speed of 1 mm/ min until rupture of the bond. Stereomicroscope was used to observe the fracture modes. The mean bond strengths were compared using one-way ANOVA and LSD tests. Results Mean microtensile bond strengths were （28.74 ± 5.15）MPa for Group AB2 , （ 25.85 ± 3.37 ） MPa for Group PB , （ 20. 60 ±2. 96 ） MPa for Group FB, （ 22. 93 ± 3.97 ） MPa for Group Xeno and （25.67±4. 72） MPa for Group iBond. The bond strengths of Group AB2 was greater than those of the other three groups （ P 〈 0. 05 ） except PB group. The bond strengths of Group Xeno and Group FB were not significantly different. The bond strengths of Group PB and Group iBond were not significantly different. Stereomicroscope examinations indicated that the adhesive failure was the most mode of fracture. Conclusion The microtensil bond strengths of five dentin adhesive systems to normal human dentine were different and in the three steps total-etching adhesive All-Bond 2 e