ABSTRACT
Objective: To study the effect of Matrilin-4 on the reparative dentin formation in the rats after dental pulp injury, and to explore its possibility to be used as a new capping agent. Methods: A total of 28 male Wistar rats were selected. A cavity on the occlusal surface of maxillary first molars on both sides was prepared in each rat. Matrilin-4 was applied on the left exposed pulp (Matrilin-4 group), and PBS was applied on the right exposed pulp (PBS group); and the cavities in both sides were covered with glass ions. On days 3, 7, 14 and 28 after operation, the rats were sacrificed, and the maxillary first molars on both sides of the rats were selected. HE staining and immunohistochemistry staining were used to observe and analyze the reparative dentin formation and the expression of dentin sialoprotein (DSP) in the odontoblasts. Results: The HE staining results showed that there were less inflammatory cells under the exposed pulp in that Matrilin-4 group at 3 d after operation compared with PBS group, and obvious vasodilation was found. At 7 d after operation, the inflammatory reaction under the exposed pulps in two groups was aggravated, but the inflammatory reaction in Matrilin-4 group was significantly lighter than that in PBS group, and the prophase dentin formation was found. After injury of 14 d, the pulp-exposed areas were covered by more complete dentin bridge in Matrilin-4 group; at 28 d after operation, compared with PBS group, there was a thick, complete and reparative dentin bridge under the exposed pulps, composed of tubular dentin in Matrilin-4 group, and there were reorganized odontoblastic layers beneath the dentin bridge. The results of immunohistochemistry showed that the positive expression strengths of DSP in the odontoblasts of the rats in two groups were gradually increased at 3, 7 and 14 d after operation, and were decreased at 28 d. The positive expression strengths of DSP in the odontoblast of the rats in Matrilin-4 group were stronger than those in PBS group at each time point after operation, and the positive expression strength reached the peak at 14 d. Conclusion: Compared with PBS group, the positive expression strength of DSP in the odontoblasts of the rats in Matrilin-4 group had significant differences (P<0.01) at 3, 7 and 14 d.
ABSTRACT
@#Crown pulp regeneration is a method to replace the pulp-capping agent with stem cells and scaffold structures, which are placed on the section of healthy root pulp tissue after pulpotomy to regenerate the pulp-dentin complex in the crown. This paper reviews the significance, physiological basis, application and challenges of crown pulp regeneration to provide new ideas for the study of pulp regeneration. The results of a literature review show that the combination of traditional pulpotomy, stem cell biology and tissue engineering, as well as the regeneration of crowns and pulp by using the tissue repair potential of healthy root pulp can effectively promote the regeneration of dentin and parts of pulp. In recent years, with the development of research on pulp regeneration, many challenges have been gradually revealed. It is necessary not only to select the treatment methods that can promote the proliferation and differentiation of dental pulp stem cells safely and effectively but also to continue to explore the scaffold materials suitable for the structural and functional diversity of the pulp chamber.