3种粘结剂对龋损内层牙本质粘结强度的研究

Microtensile bond strengths of three adhesives to normal or caries-affected dentine

目的:比较3种粘结剂对正常和龋损内层牙本质的粘结强度。方法:18颗近中牙合面中龋人离体磨牙,在龋检液监控下用慢速球钻去龋,在远中牙合面健康牙本质上制备相同深度窝洞作为对照组。按完全随机化的方法分成3组,用3种粘结剂粘接(Prim e&Bond NT、Adper Prompt、Contax)粘结,然后复合树脂(Ch-rism a A2)充填。制备用于测试微抗拉粘结强度的条状试件,在拉力试验机上测定粘结强度,扫描电镜观察断裂模式。结果:3种粘结剂对龋损内层牙本质和正常牙本质的粘结强度分别为:Prim e&Bond NT(16.26±4.73)MPa,(20.36±10.18)MPa;Adper Prompt(20.19±4.04)MPa,(23.01±7.34)MPa;Contax(27.73±8.82)MPa,(26.32±8.26)MPa,试件断裂以混合破坏为主。结论:3种粘结剂龋损内层牙本质的粘结强度与正常牙本质无显著差异。

Objective：To evaluate the micro-tensile bond strengths （mTBS）of one total-etching and two self-etching bonding agents to normal dentin （ND） or caries-affected dentin （CAD）. Methods： Eighteen extracted human molars with medial coronal carious lesions extending into mid-dentin were selected. The softened carious dentine was removed with a slow-speed, carbon-steel bur and Caries Marker（Voco） was used as a guide. Prepared cavity in sound dentin in the distal coronal part of the identical teeth was used as the control. One of the three self-etching bonding agents,Adper Prompt（3M）,Contax （DMG） and Prime＆Bond NT （Dentsply） was applied to each tooth respectively. After the adhesive on all specimens was photo-cured, Chrisma resin （Kulzer） was built up and then photo-polymerized. Matchstick-shaped samples through the bond interfaces were sectioned and then subjected to the microtensile bond test at a cross-head speed of 1.0 mm/min. Results：The mTBS（MPa） of Prime＆Bond NT to CAD and ND was 16.26 ±4.73 and 20.36 ± 10.18（P 〉0.05） ,that of Adper Prompt 20.19 ±4.04 and 23.01 ±7.34 Mpa（P 〉 0.05 ）, Contax 27.73 ± 8.82 and 26.32 ± 8.26 （ P 〉 0.05 ）, respectively. The fractured adheisive dentin surface was mainly a mixed failue mode. Conclusions： There is no significant difference in the bond strengths of each of the three bonding agents to ND and CAD.