Effects of mineral trioxide aggregate and calcium hydroxide on the proliferation and differentiation capacity of pulp cells of primary teeth / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the effects of mineral trioxide aggregate (MTA) and calcium hydroxide on the proliferation and differentiation capacity of pulp cells of primary teeth.</p><p><b>METHODS</b>Pulp cells were isolated from the retained primary teeth without apparent root resorption and cultured. The cells of 4 - 8 passages were used in the study. Cell proliferation was detected by MTT array, von Kossa staining employed to observe the formation of mineralized nodules and mRNA expression of alkaline phosphatase (ALP) and dentin sialophosphoprotein (DSPP) determined by real time PCR.</p><p><b>RESULTS</b>MTA-treated cells proliferated significantly faster than the other two groups (F = 1835.065, P < 0.01), while calcium hydroxide-treated cells grew slower than the control significantly (F = 1792.301, P < 0.01). The formation of mineralized nodules was found in both MTA-treated and calcium hydroxide-treated pulp cells. The number of mineralized nodules showed no significant difference between the two groups (P > 0.05). Either ALP or DSPP mRNA expression showed significant difference among the three groups (F = 349.651, P < 0.01; F = 1653.001, P < 0.01). MTA increased mRNA expression of ALP and DSPP in pulp cells (P < 0.01), whereas calcium hydroxide down-regulated them (P < 0.01).</p><p><b>CONCLUSIONS</b>MTA is more suitable than calcium hydroxide as pulp-capping agent in primary teeth.</p>

Bone formation in vitro and in vivo by human bone marrow-derived mesenchymal stem cells / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To culture and study the osteogenic characteristics of human bone marrow-derived mesenchymal stem cells (hBMMSCs).</p><p><b>METHODS</b>hBMMSCs were separated and cultured from human iliac crest marrow. Growth kinetics of hBMMSCs was studied by growth curve. Under the osteoinductive culture, osteogenic differentiation of hBMMSCs was tested by alkaline phosphatase (ALP). Osteogenic functions of hBMMSCs in vitro and in vivo were also respectively detected by von Kossa stain and by transplanting hydroxyapatite/tricalcium phosphate ceramics (HA/TCP) with hBMMSCs.</p><p><b>RESULTS</b>hBMMSCs were cultured successfully. The growth curve of the second passage of BMMSCs indicated that the time of population doublings was about 3.5 days. The results of ALP stain were evident by the significant increase in ALP activity after hBMMSCs cultured in osteoinductive medium. Some mineralized nodules were detected by von Kossa stain at nineteenth day of osteoinductive culture. In vivo assay, histological evalution showed bone formation in 3 months after grafts of HA/TCP with hBMMSCs.</p><p><b>CONCLUSIONS</b>Osteoinductive solution can induce hBMMSCs to differentiate osteogenetic cell lines. Mineralized nodules and bone formation were found in vitro and in vivo assay. The results demonstrate that hBMMSCs have the potential for osteogenesis.</p>