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目的:探讨新型自固化树脂充填Ⅴ类洞后充填体的表面边缘和内部界面适合性。方法:选用因正畸需要拔除的无龋人上颌前磨牙56颗（首都医科大学口腔医学院口腔颌面外科提供），制备Ⅴ类洞，分为2组（每组28颗）。实验组用预处理剂（Tooth primer）和新型自固化树脂（Bondfill SB）充填，对照组用自酸蚀粘接剂（Scotchbond Universal）和光固化复合树脂（Z100）充填。充填后样本牙进行疲劳实验：机械循环加载（49 N、1 Hz频率120万次）和冷热循环加载（5和55 ℃的水中分别浸泡1 min，共3 000次），模拟口腔环境的咀嚼负荷和温度变化。疲劳实验前后样本牙浸入50%氨化硝酸银溶液并还原银离子。用扫描电镜检测分析充填体表面完整边缘百分率和内部界面银沉淀物长度。用透射电镜观察牙本质界面超微结构。结果:扫描电镜显示，疲劳实验前实验组牙本质表面边缘间隙较对照组小。疲劳实验前对照组牙釉质界面银沉淀物长度[（0.67±0.15）μm]显著小于实验组[（33.54±10.27）μm]（n P<0.05）。疲劳实验后对照组牙釉质表面完整边缘百分率[（55.08±15.20）%]显著大于实验组[（25.15±12.47）%]（n P<0.05）。疲劳实验后实验组充填体表面和内部更易观察到内聚破坏。透射电镜显示，疲劳实验前对照组牙本质界面比实验组有更多的银沉淀物；疲劳实验后对照组牙本质界面破坏主要发生于混合层下方；实验组牙本质界面破坏主要发生于混合层下方和充填体内部。n 结论:充填Ⅴ类洞时本项研究所用光固化复合树脂在牙釉质界面有较好的表面边缘和内部界面适合性，而新型自固化复合树脂在牙本质界面有良好的表面边缘和内部界面适合性。“,”Objective:To investigate the superficial and internal adaptations of a new self-curing composite resin in Class Ⅴ cavities.Methods:Class Ⅴ cavities were prepared in 56 caries-free human maxillary premolars (collected from Department of Oral and Maxillofacial Surgery, Capital Medical University School of Stomatology) extracted for orthodontic reasons, and these premolars were assigned into two groups (28 specimens each group). Experimental group were restored with a pretreating agent (Tooth primer) and a new self-curing composite resin (Bondfill SB). Control group were restored with a self-etching adhesive (Scotchbond Universal) and a light-curing composite resin (Z100). The restored teeth were subjected to a fatigue test to simulate temperature change and occlusal load in oral environment: mechanical cycles (1 200 000 cycles at 49 N with a frequency of 1 Hz) and thermocycles (3 000 cycles from 5 ℃ to 55 ℃ with a dwelling time of 1 min each). Before and after fatigue test, restored teeth were immersed in an 50% ammoniacal silver nitrate solution and reduced. Superficial perfect margin percentage value and length of silver deposit along the internal interface were quantified by scanning electron microscopy (SEM). Ultrastructure of dentin bonding interface was analyzed by transmission electron microscope (TEM).Results:Before fatigue test, superficial gaps at dentin side in the specimens in experimental group were narrower than those in control group, and length of silver deposit at enamel side [(0.67±0.15) μm] in specimens in the control group was significantly lower than that in the experimental group [(33.54± 10.27) μm] ( n P<0.05). After the fatigue test, control group showed higher perfect margin percentage value to enamel [(55.08±15.20)%] than experimental group [(25.15±12.47)%] did (n P<0.05). After the fatigue test, cohesive failures could be more easily found in experimental group than in control group at surficial and internal interfaces. In TEM results, more silver deposits were found at dentin bonding interface in control group than in experimental group before the fatigue test. After the fatigue test, the deterioration at dentin bonding interface mostly happened at the bottom of the hybrid layer in control group, while in experimental group it could be found at the bottom of the hybrid layer and in the restorative material.n Conclusions:When restored in Class Ⅴ cavity, the studied light-curing composite shows better superficial and internal adaptations for enamel than the new self-curing composite resin and the new self-curing composite resin shows good superficial and internal adaptations for dentin.