Dental pulp repair with dental pulp stem cells by construction of tissue-engineered dentin-pulp complex / 中国组织工程研究

ABSTRACT

BACKGROUND: Studies have shown that dental pulp stem cells have high proliferation and multi-directional differentiation abilities and can differentiate into a variety of cells under certain conditions. At present, the use of dental pulp stem cells to construct tissue-engineered dentin-pulp complex is expected to become a new strategy for human dental defect repair . OBJECTIVE: To observe the effect of dental pulp stem cells on the repair of rat tooth defects by construction of tissue-engineered dentin-pulp complex. METHODS: Twenty-four Sprague-Dawley rats were used to make animal models with dental pulp removal, and then model rats were randomly divided into model group and transplantation group. Rats in the transplantation group were subjected to tissue-engineered dentin-pulp complex transplantation, and those in the model group given no treatment. Tooth samples were collected at 3, 5, 7 weeks post transplantation and observed using hematoxylin-eosin staining and immunofluorescence staining. The dentin thickness of rats was measured by Image Pro Plus 6.0 image software system. RESULTS AND CONCLUSION: (1) Dental pulp cells was mostly spindle/oval-shaped and partially polygonal. The third generation of cells with long spindle shape showed fibrous growth and uniform morphology. Findings from immunohistochemical staining showed spindle-shaped deep-colored cells with oval nuclei stained as dark blue were identified as fibroblast-like cells, and were positire for vimtin. (2) Findings from hematoxylin-eosin staining showed vacuolar degeneration of the cells, and hbdestroyed pulp tissue and debris, irregular cord-like tissue, and a large amount of red blood cells and inflammatory cells in the pulp cavity, accompanied by clearly visible vascular dilation. Seven weeks after transplantation, a bundle of odontoblasts were visible in the matrix-like tissues of the dentin, and there was a distinct boundary between the original dentin and regenerated dentin. (3) Findings from immunofluorescent staining showed that after dentin-pulp complex transplantation, the number of cells in the pulp cavity increased significantly at 3 weeks, and there was also a substantial increase in dental pulp cells at 5 weeks that were distributed on the wall of the pulp cavity. Compared with the model group, the dentin thickness in the transplantation group was significantly higher at each time after transplantation (P < 0.05), and in the transplantation group, there was also a significant difference in the dentin thickness at different time points (P < 0.05). To conclude, the tissue-engineered dentin-pulp complex can promote dentin regeneration and repair.