改良人工唾液浸泡对三种牙本质粘接剂微拉伸强度的影响

The effect of modified artifical saliva on the microtensile bond strengths of three adhesives

目的:评价含细菌的人工唾液对临床上常用的3种牙本质粘接剂微拉伸粘接强度的影响。方法:18个新鲜拔除的无龋第三磨牙垂直牙体长轴除去冠部釉质,暴露中层牙本质,随机分成3组,分别用粘接剂Prime&Bond NT(NT)、Adper Prompt(AP)、Contax粘接,复合树脂分层堆砌。37℃水浴中浸泡24h后制备测试微拉伸粘接强度的条状试件,放入含细菌的人工唾液中,分别在即刻、1周、1月、3月时分别取出10个进行微拉伸强度测定。结果:3组粘接剂在即刻、1周、1月、3月时的微拉伸强度分别为:NT(42.07±11.75)MPa、(37.73±8.74)MPa、(29.30±7.56)MPa、(24.93±7.60)MPa;AP(25.86±7.49)MPa、(22.94±4.66)MPa、(17.51±4.20)MPa、(13.83±3.94)MPa;Contax(45.35±9.64)MPa、(40.79±10.64)MPa、(35.11±9.41)MPa、(27.59±7.37)MPa。试件断裂以混合破坏为主。结论:水和细菌的存在可能会协同加速粘接界面的老化,导致粘接强度的下降。

Objective： The aim of this study was to evaluate the microtensile bond strengths （mTBS） of three clinical dentin adhesives after soaked in artifieal saliva with bacteria. Method： The enamel of occlusal surfaces of 18 the third molars without caries extracted freshly was removed perpendicular to the long axis with a diamond bur under water. The medial dentin was exposed. Then the 18 teeth were randomly divided into 3 groups. Prime＆Bond NT （NT）, Adper Prompt （AP） and Contax were applied to each group respectively.After the adhesives on all specimens were photo-cured, Chrisma resin was piled up to them. Matchstick-shaped samples through the bond interfaces were sectioned for the microtensile bond test. These samples were immersed in artifical saliva with bacteria and the microtensile bond strength （mTBS）of that was mea- sured afer 0 day, 7 day, 30 day and 90day differently. Result： The mTBS of the three groups at 0 day, 7 day, 30 day and 90 day was as follows： NT （42.07± 11.75） MPa, （37.73±8.74） MPa, （29.30±7.56） MPa, （24.93±7.60） MPa; AP （25.86±7.49） MPa, （22.94±4.66） MPa, （17.51 ±4.20） MPa, （13.83±3.94） MPa; Contax （45.35±9.64） MPa, （40.79± 10.64） MPa, （35.11±9.41 ） MPa, （27.59±7.37） MPa. The fractured adhesive dentin surface was mainly a mixed failure mode. Conclusion： saliva and bacteria may have a synergistic effect on the degradation of the bonded interface which led to the decrease of the bond strength.