The role of vitamin D receptor in predentin mineralization and dental repair after injury

Dentin is a permeable and complex tubular composite formed by the mineralization of predentin that mineralization and repair are of considerable clinical interest during dentin homeostasis. The role of Vdr, a receptor of vitamin D, in dentin homeostasis remains unexplored. The aim of the present study was to assess the impact of Vdr on predentin mineralization and dental repair. Vdr-knockout (Vdr^−/−) mice models were constructed; histology and immunohistochemistry analyses were conducted for both WT and Vdr^−/− mice. The finding revealed a thicker predentin in Vdr^−/− mice, characterized by higher expression of biglycan and decorin. A dental injury model was employed to observe tertiary dentin formation in Vdr^−/− mice with dental injuries. Results showed that tertiary dentin was harder to form in Vdr^−/− mice with dental injury. Over time, heightened pulp invasion was observed at the injury site in Vdr^−/− mice. Expression of biglycan and decorin was reduced in the predentin at the injury site in the Vdr^−/− mice by immunohistochemistry. Taken together, our results imply that Vdr plays a regulatory role in predentin mineralization and tertiary dentin formation during dentin homeostasis.