目的：观察不同生物活性盖髓材料在初始凝固及完全凝固后，与自酸蚀或酸蚀冲洗粘接系统之间的粘接强度。方法：制备三氧化矿物凝聚体（mineral trioxide aggregate，MTA）、iRoot BP Plus（BP）及iRoot FS（FS）试件各60个，分成三组，分别在材料初始凝固时间（MTA 4 h，BP 2 h，FS 20 min）、24 h、7 d三个时间点对材料表面进行粘接处理，将各材料组随机分为两组，分别用通用粘接剂（Single Bond Universal，SBU）自酸蚀模式或酸蚀冲洗模式进行粘接（n=10），限制粘接面积为直径3 mm圆形，上方制作复合树脂柱后测试其剪切强度并记录断裂模式，计算剪切粘接强度值后采用SPSS 19.0软件中的方差分析方法进行统计分析。采用扫描电镜观察凝固后材料表面形貌及经过不同酸蚀处理后的表面微观形态。结果：三种材料的自酸蚀和酸蚀冲洗粘接强度在初始凝固、7 d时的粘接强度比较差异均无统计学意义（P<0.05）；凝固24 h后，MTA的自酸蚀和酸蚀冲洗粘接强度均显著高于FS与BP（P<0.05）；同种材料完全凝固后粘接强度均显著高于初始凝固组；各组试样断裂均为盖髓材料内聚破坏。扫描电镜下可见三种材料表面特征性晶体结构，MTA表面晶体较另外两者大；经酸蚀处理后，三种材料表面晶体特征均有不同程度破坏。结论：本研究范围内，FS在较短初始凝固时间即可获得一定的粘接强度，与初始凝固时MTA和BP粘接强度无明显差异。临床条件下可以在盖髓材料初始凝固（20 min）后进行树脂直接修复，以提高临床效果与效率。

Objective： To investigate influence of setting time on bond strength of different bioactive pulp capping materials with self-etch or etch-and-rinse adhesive. Methods: Sixty specimens were prepared for each of the three tested capping materials, namely mineral trioxide aggregate (MTA), iRoot BP Plus (BP) and iRoot FS (FS). Specimens of each material were divided into three groups and bonded at three setting time points of the materials respectively: initial setting time (4 h for MTA, 2 h for BP and 20 min for FS), 24 h after application and 7 d after application. The specimen surfaces of each group were treated with self-etch mode or etch-and-rinse mode of one universal adhesive (Single Bond Universal, SBU) (n=10). The bonding area was restricted to a round area with 3 mm diameter, on which composite cylinders were build up with flowable composite and light cured completely. The shear bond strength was tested immediately with a shear strength tester and fracture mode was observed under stereo microscope and recorded. The mean shear bond strength for each group was analyzed with SPSS 19.0 software ANOVA method. The surface morphology of each material was observed after setting and acid treatment under scanning electron microscope. Results: There was no significant difference among the three tested materials at either initial setting point or 7 d after application (P<0.05). The bond strength of MTA was significantly higher than those of BP and FS 24 h after application in both bonding modes (P<0.05). For all the three tested materials, shear bond strength was significantly higher for complete setting group than for initial setting group of the same material (P<0.05). Under scanning electron microscope, the characteristic crystal patterns could be observed on the three bioactive materials surfaces after complete setting, the size of which was bigger for MTA than for BP and FS. These features were lost to some extent after self-etch primer application or phosphoric acid etching. Conclusion: Based on the present results, adequate bond strength can be obtained for FS at initial setting time, which is comparable with BP and MTA. This implies that clinically composite restoration can be placed over bioactive direct capping materials after shortened initial setting process in one visit.