摘要目的:比较3种类型大块树脂的固化深度、硬度及应用于乳牙的微渗漏情况，为临床应用提供参考。方法:对照组为A组（常用复合树脂Filtek TM Z350 XT）和B组（树脂复合体Beautifil Ⅱ）；大块树脂组分别为C组（高黏型Filtek TM Bulk Fill）、D组（黏度可变型SonicFill 2）和E组（低黏型SDR ? flow+）。扫描电镜观察各组材料固化后微观形貌；制备各组树脂固化试件（每组6个），显微硬度计测量各组试件表层及不同深度的维氏硬度值并计算固化深度；分别用各组树脂充填离体乳磨牙（每组5颗），切片、老化、银离子染色、显影，扫描电镜下观察各组标本微渗漏情况，对5组银离子渗漏占比评定分级，采用了Jonckheere-Terpstra秩和检验进行统计学分析。 结果:扫描电镜观察显示：A、C组填料颗粒呈球形且分布均匀；B、D和E组填料颗粒为多角形且分布不均匀。A、B、C、D、E组表面硬度分别为（84.97±6.30）、（65.04±5.95）、（57.80±1.18）、（60.77±2.34）、（33.32±1.83）MPa，A组硬度最高，E组硬度最低，A、E组与其他各组相比差异均有统计学意义（ P<0.05）。B、C、D组硬度相似，3组间总体比较及组间两两比较差异均无统计学意义（ P>0.05）。A、B、C、D和E组的固化深度分别为2.6、3.4、5.8、3.8和7.8 mm。E组微渗漏最严重［0级占2%（1/50）、1级占22%（11/50）、2级占30%（15/50）、3级占24%（12/50）、4级占22%（11/50）］，其微渗漏分级分布与其他组相比差异均有统计学意义（ P<0.05），其他各组间微渗漏分级分布差异均无统计学意义（ P>0.05）。 结论:高黏型和黏度可变型大块树脂硬度和微渗漏与树脂复合体相似，固化深度更大，可作为乳牙充填的一种选择。

abstractsObjective:To compare the depth of cure, surface hardness and microleakage applied to primary teeth of three types of bulk-fill resins, so as to provide reference for clinical application.Methods:Composite resin Filtek TM Z350 XT (group A) and giomer Beautifil Ⅱ (group B) were used as controls, high-viscosity bulk-fill resin Filtek TM Bulk Fill (group C), sonic-activated bulk-fill resin SonicFill 2 (group D) and flowable bulk-fill resin SDR ? flow+(group E) were studied. The microstructure of each group was observed by scanning electron microscope (SEM). Specimens of each group were prepared (6 pieces per group), and the Vickers microhardness of the surface layer and different depths of each group were measured, and then the depths of cure were calculated. Twenty-five primary molars dentin were filled by resins of each group (5 teeth per group), sliced, then aged, slices of each group were developed by silver ion staining. SEM was used to observed the distribution of silver ions. Microleakage of each group were analyzed by Jonckheere-Terpstra rank sum test. Results:SEM showed that the filler particles in groups A and C were spherical and evenly distributed. The shape of the fillers in groups B, D and E were polygonal and unevenly distributed. The surface hardness of groups A, B, C, D and E were (84.97±6.30), (65.04±5.95), (57.80±1.18), (60.77±2.34), (33.32±1.83) MPa respectively. Group A had the highest hardness, while group E was the lowest, and the differences between the two groups and other groups was statistically significant ( P<0.05). There were no statistically significant differences among groups B, C, and D ( P>0.05). The curing depths of groups A, B, C, D and E were 2.6, 3.4, 5.8, 3.8 and 7.8 mm respectively. The largest microleakage was found in group E [2% (1/50) for grade 0, 22% (11/50) for grade 1, 30% (15/50) for grade 2, 24% (12/50) for grade 3, and 22% (11/50) for grade 4], which was statistically different from other groups ( P<0.05). No statistically significant differences were found among other 3 groups ( P>0.05). Conclusions:Both high-viscosity and sonic-activated bulk-fill resins have the greater depth of cure, the same hardness and microleakage as giomer, which might be an option for restoration in primary teeth.