目的：使用显微CT观察不同牙体修复材料用于Ⅱ类洞充填修复时材料与龈壁的适合性。方法：选择人离体前磨牙18颗，制备邻牙合面Ⅱ类洞，随机分为6组进行分层充填。使用6种材料作为龈壁层材料，包括4种注射式充填材料：Beautifil Flow Plus F00（F00）、Beautifil Flow F10（F10）、Filtek Z350 Flowable（Z350F）和FujiⅡ LC CAPSULE（Fuji），以及2种膏体状填压式充填材料：BeautifilⅡ（BF）和Filtek Z350（Z350）。将充填修复后离体牙进行显微CT扫描和三维重建，分析龈壁层充填体牙齿界面孔隙体积和分布。孔隙体积采用Jonckheere-Terpstra非参检验方法进行统计分析。结果：龈壁层充填体-牙齿界面孔隙体积（mm3）由小到大依次为：Z350F（0.000 15）、F10（0.000 39）、F00（0.012）、Fuji（0.070）、Z350（0.16）和BF（0.20），Z350F/F10组与Fuji/Z350/BF组差异具有统计学意义（P<0.05）。孔隙分布结果显示，绝大多数孔隙位于窝洞的点线角。结论：龈壁层充填体牙齿界面孔隙主要位于窝洞点线角，高流动注射式充填材料可以有效减少界面孔隙的产生。

Objective: To evaluate the adaptation of different materials for gingival layer in Class Ⅱ restorations using Micro-CT.  Methods: Eighteen extracted human premolars were selected, and Class Ⅱ cavities were prepared. The teeth were randomly divided into six groups and restored using layering technique. Six materials were used for gingival layer, including four injectable materials: Beautifil Flow Plus F00 (F00), Beautifil Flow F10 (F10), Filtek Z350 Flowable (Z350F), FujiⅡ LC CAPSULE (Fuji), and two packable materials: BeautifilⅡ (BF), Filtek Z350 (Z350). The restored teeth were scanned with micro-CT and the images were 3D reconstructed to evaluate the volumes and the distribution of the voids on the restorationtooth interface of the gingival layer. The volume of the voids were statistically analyzed using nonparametric Jonckheere-Terpstra tests. Results: The volumes (mm3) of the voids on the restorationtooth interface were: Z350F (0.000 15), F10 (0.000 39), F00 (0.012), Fuji (0.070), Z350 (0.16) and BF (0.20). There were significant differences between Z350F/F10 and Fuji/Z350/BF (P<0.05). Most of the voids were found on the point-line angles of the cavities. Conclusion: The voids on the restoration-tooth interface were mainly on the point-line angles of the cavities. Injectable materials with high flowablility could reduce the restorationtooth interface voids significantly when used for the gingival layer in Class Ⅱ restorations.