RESUMO
BACKGROUND/AIM: The viability of periodontal ligament cells on the root surface is a major factor that influences the healing of replanted teeth. A suitable storage medium is necessary to preserve avulsed teeth before replantation. Conditioned medium from placenta-derived mesenchymal stem cells (PMSC-CM) contains a variety of growth factors. The aim of this study was to evaluate the effectiveness of PMSC-CM as a storage medium to maintain the cell viability of avulsed teeth. MATERIAL AND METHODS: Extracted premolars from healthy humans were randomly stored in Hank's balanced salt solution (HBSS) and PMSC-CM for 6, 12 and 24 hours, respectively, at room temperature, and then the ratio of apoptosis of the periodontal ligament (PDL) cells was identified by flow cytometry. Human periodontal ligament stem cells (PDLSCs) were incubated with HBSS and PMSC-CM, respectively, for 6, 12, 24 and 48 hours in 5% CO2 at 37°C. Then, the cell viability of PDLSCs was determined using the cell counting kit-8 (CCK-8) and a cell cycle assay was performed. RESULTS: The apoptosis rate of PDL cells in PMSC-CM was significantly lower than that in HBSS at 24 hours (P < .001), while the two groups showed similar cell apoptosis rates at 6 and 12 hours (P > .05). The cell proliferation of PDLSCs treated with PMSC-CM significantly increased compared with the HBSS group (P < .05). The cell cycle assay revealed that the PDLSCs treated with HBSS were arrested at the G1 phase, while there was no difference between the PMSC-CM group and the control group (P > .05). CONCLUSIONS: Compared with HBSS, PMSC-CM showed better inhibition of apoptosis of PDL cells and promoted the proliferation of PDLSCs. Thus, PMSC-CM could be a promising storage medium for avulsed teeth.