Biological Effects of bioactive glass and natural coral on periodontal ligament fibroblast-like cell behavior / 대한치주과학회지

The purpose of this study was to evaluate the effects of bioactive glass and natural coral on the human periodontal ligament fibroblast(HPLF) behaviors during the regeneration process of peridontium. To determine the cellular events occuring in the presence of the particles of bioactive glass and natural coral, HPLF were isolated from healthy premolar teeth extracted for orthodontic treatment. Cells were cultured in alphaMEM at 37degrees C, 5% CO2, 95% humidity incubator. Bioactive glass and natural coral were powdered, and each particled(<40micrometer) were placed on the cultured cells at the concentration of 0.3mg/ml, and l,0mg/ml for experimental group. In control group no particles were added. And each group was evaluated by examining the cell morphology under phase-contrast micrograph at 4 day and transmission electron micrograph(TEM) and scanning electron micrograph(SEM) at 14 day, alkaline phosphatase activity at 5 and 9 day, protain synthesis at 4 day, DNA synthesis at 1, 2, 3 and 4 day, cell proliferation at 1, 3, 5,7 and 9 day and the formation of bone nodule at 30 day after culturing all groups in mineralizing supplemented mediun. No significant changes in cell morphology by adding these two matirials were found under phase contrast microscopy and TEM, HPLF phagocytocized each particles suggesting that HPLF is involved in the process of resorbing each particles and that bioactive glass were more biocompatible than natural coral. The ALPase activity of bioactive glass 0.3 mg/ml was similar with control groups and all the rests of control groups were significantly low(P<0.01) indicating a transient dedifferentiation of HPLF in the presence of bioactive glass and natural coral particles. There were no significant differences of protein synthesis between all groups. The DNA synthesis in experimental groups were significantly lower than control groups at 1, 2 and 3 day (P<0.01) but became similar to control groups at 4 day. Between control groups, the DNA synthesis in bioactive glass 0.3mg/ml group was significantly higher than other groups(P (0.01). Cell proliferation in natural coral 1.0mg/ml and bioactive glass l.0mg/ml groups were significantly lower than control group at 3 day(P(0.05) and there were no differences at 5, 7, 9 day. There were more bone nodule formation in experimental groups than in control groups. In conclusion, these results indicated that bioactive glass and natural coral have some effects of a transient dedifferentiation on HPLF and regeneration of periodontal tissues, however any significant cytotoxic effect on HPLF by these two particles were not found.

The effect of a static magnetic field on the bone nodule formation of MC3T3-E1 cells / 대한치과교정학회지

To evaluate the effect of a static magnetic field on the bone producing potential of MC3T3 El cells, the alkaline phosphatase activity was measured after the cells having been cultured under 76.4mT static magnetic field using a SmCos magnets for 5days, 7days, lldays, 15days and 2ldays for each cell culture group. Also, the amount of bone nodule stained with Alizarin red S was observed. The results were as follows. · The alkaline phosphatase activity of the 7, 11, and 15 days group among the experimental groups was decreased as compared with the control groups, and the decrease of alkaline phosphatase activity in the 11 days group was the most evident among them. · Any stained bone nodules of both groups had not been observed until the 11th day. The stained bone nodules in the control groups were found on the 15th day, but not in the experimental groups. The stained bone nodules were observed in both groups on the 21st day, but the control groups have more bone nodules than the experimental groups.