Effects of the prevention of medication-related osteonecrosis of the jaw by local administration of a dental pulp stem cell-conditioned medium to the rat tooth extraction socket.

The onset of osteonecrosis of the jaw, which is a side effect of bisphosphonates, often develops after tooth extraction; measures for its prevention have not yet been established. While treatment with systemic administration of bone marrow stem cell-derived conditioned medium for medication-related osteonecrosis of the jaw (MRONJ) has been reported, its preventive effects have not been clarified yet, and the high degree of invasiveness of bone marrow fluid collection remains an issue. Therefore, we created a rat model of MRONJ using BP zoledronic acid, used a dental pulp stem cell-conditioned medium (DPSC-CM), which can be collected relatively easily, and locally applied it to the tooth extraction socket with atelocollagen and gelatin sponges. The preventive effect on the onset of MRONJ was subsequently examined. The results demonstrated that the bone exposure width of the extraction socket was reduced, and the mucosal covering was promoted in the atelocollagen + DPSC-CM group as compared with the other groups. Furthermore, histological results indicated a decrease in the number of empty bone lacunae, whereas immunohistochemical staining revealed the presence of many vascular endothelial growth factor (VEGF)-positive cells. Moreover, the results of the investigation of the sustained release of atelocollagen using VEGF indicated the release of VEGF over time. Our results suggest that local administration of DPSC-CM using atelocollagen may be a useful method for the prevention of MRONJ triggered by tooth extraction.