目的:使用基于光学相干断层扫描(OCT)图像的数字图像相关(DIC)分析检查不同树脂基复合材料(RBC)修复体的聚合收缩。
方法:三种红细胞的折射率(RI),FiltekZ350XT(Z350),Z350Flowable(Z350F),和后填充(填充),在聚合之前和之后测量以在OCT下校准它们的轴向尺寸。在牛门牙中制备I类空腔,并在非粘合和粘合条件下分别填充这些RBC。在20s光聚合过程中捕获这些修复体的一系列OCT图像,然后将其输入DIC软件以分析其收缩行为。还使用这些OCT图像检查界面适应。
结果:三种复合材料的RI范围为1.52至1.53,光聚合导致RI值的可忽略增加。对于非粘合修复体,Z350F显示顶面的最大垂直位移(-16.75µm),其次是堆积物(-8.81µm)和Z350(-5.97µm)。在他们的粘合条件下,都显示位移增加。在底部表面的位移测量中观察到很大的变化。在时间分析中,非粘结Z350F和堆积体的收缩在6-10s后减速。然而,Z350在8.2s后显示出反弹的向上位移。在未粘结的Z350和Z350F修复体中发现了明显的界面间隙。
结论:基于新型OCT图像的DIC分析提供了在整个聚合过程中复合修复体的收缩行为和脱粘的全面检查。可流动的复合材料显示出最高的收缩位移。在非粘合的常规复合修复体中可能会发生收缩方向的变化。
OBJECTIVE: To examine the polymerization shrinkage of different resin-based composite (RBC) restorations using optical coherence tomography (OCT) image-based digital image correlation (DIC) analysis.
METHODS: The refractive index (RI) of three RBCs, Filtek Z350XT (Z350), Z350Flowable (Z350F), and BulkFill Posterior (Bulkfill), was measured before and after polymerization to calibrate their axial dimensions under OCT. Class I cavities were prepared in bovine incisors and individually filled with these RBCs under nonbonded and bonded conditions. A series of OCT images of these restorations were captured during 20-s light polymerization and then input into DIC software to analyze their shrinkage behaviors. The interfacial adaptation was also examined using these OCT images.
RESULTS: The RI of the three composites ranged from 1.52 to 1.53, and photopolymerization caused neglectable increases in the RI values. For nonbonded restorations, Z350F showed maximal vertical displacements on the top surfaces (-16.75 µm), followed by Bulkfill (-8.81 µm) and Z350 (-5.97 µm). In their bonded conditions, all showed increased displacements. High variations were observed in displacement measurements on the bottom surfaces. In the temporal analysis, the shrinkage of nonbonded Z350F and Bulkfill decelerated after 6-10 s. However, Z350 showed a rebounding upward displacement after 8.2 s. Significant interfacial gaps were found in nonbonded Z350 and Z350F restorations.
CONCLUSIONS: The novel OCT image-based DIC analysis provided a comprehensive examination of the shrinkage behaviors and debonding of the composite restorations throughout the polymerization process. The flowable composite showed the highest shrinkage displacements. Changes in the shrinkage direction may occur in nonbonded conventional composite restorations.