流动树脂衬垫层与牙本质间微拉伸强度的评价

The effect of flowable resin as an intermediate liner on the micro-tensile bond strength between resin and dentin

目的：评估流动树脂作为衬垫层对其与牙本质粘结强度的影响。方法：选择30个离体磨牙制备牙本质粘结面后,随机分为3组（n=10）,分别用Z350（A组）、F350（B组）、F350（1 mm）＋Z350（C组）形成5 mm树脂“冠”。所有样本经500次冷热循环（0-5℃、55-60℃）后制备成10 mm×1 mm×1 mm的标准试件。所有试件用万能试验机测量微拉伸强度并在体视显微镜下观察试件断裂方式。结果：A、B、C组的微拉伸强度（MPa）分别为40.86±4.01、41.25±4.45、44.97±6.00（P〉0.05）;断裂方式以界面断裂为主。结论：用流动树脂作为衬垫层对树脂充填材料与牙本质的粘结强度无显著影响。

AIM： To investigate the effect of flowable resin as a liner on the micro - tensile bond strength between resin and dentin. METHODS ： Occlusal surfaces of 30 human third molars were ground to obtain flat dentin surfaces. The dentin surfaces were randomly divided into 3 groups （ n = 10）. Crowns of Z350 and Flowable Z350 （F350）with the thickness of 5 mm were prepared on the dentin surface of group A and group B respectively, the Crowns of group C were prepared by Z350 with a 1 mm layer of F350 between the crown and dentin surface. The sam- ples were thermocycled for 500 cycles （0 - 5 ℃ and 55- 60 ℃ ）, then standard specimens （ 10 mm × 1 mm × 1mm） were prepared. Micro - tensile bonding strength （ μ TBS） was tested by an universal testing machine. Mode of failure was observed by stereoscopic light microscopy. RESULTS： The p, TBS（MPa） of group A, B and C was 40.86 ± 4.01, 41.25 ± 4.45 and 44.97 ± 6.00 respectively（ P 〉 0.05 ） , the fracture of most samples were at interface. CONCLU- SION： The use of an intermediate layer did not affect the bond strength between resin and dentin.