Objective To observe the effect of different concentrations of zoledronic acid on human gingival fibroblast(HGF) cells proliferation and apoptosis, and to investigate the mechanism of bisphosphonate-related osteonecrosis of the jaw(BRONJ) caused by zoledronic acid.Methods Different concentrations(0, 0.5, 1.0, 5.0, 10.0 μmol/L) of zoledronic acid acted on the HGF.After 24 hours, flow cytometry was used to detect the rate of apoptosis and methyl thiazolyl terazolium(MTF) assay used to observe the proliferation of HGF.The effect of different concentrations of zoledronic acid on cell proliferation was examined by proliferation test on day 2, 4 and 7.Results Flow cytometry showed that when the concentration of zoledronic acid was 0, 0.5, 1.0, 5.0, 10.0 μmol/L, the apoptosis rate was (0.67± 0.50)％, (2.13±0.21)％, (3.27±0.23)％, (4.17±0.35)％, (9.87± 1.79)％ respectively.The difference in HGF cells between control group and zoledronic acid groups was significant(P＜0.05) at three concentrations of zoledronic acid(1.0, 5.0, 10.0 μmol/L).The cell proliferation test showed an concentration-time dependent effect.With increase of concentration and time, the cell proliferation was significantly inhibited.There was significant difference in absorbance value among the different concentration groups(P＜0.05).Conclusions Zoledronic acid can inhibit HGF proliferation and promote its apoptosis.

Objective: To investigate the association of periodontal diseases in pregnant women with preterm birth and low birth weight. Methods: 213 pregnant women aged 22-40 years were enrolled while receiving periodontal examination by 26 weeks of gestation. Periodontal measurements included plaque index(PLI),bleeding on probing (BOP),probing pocket depth(PD) and clinical attachment loss(CAL) were used as the criteria to classify the groups: healthy group(HG; n = 63),gingivitis group(GG; n = 74) and periodontitis group(PG; n = 76). At delivery,birth date and birth weight were recorded. Results: Preterm birth ratio in PG group is higher than that in HG group and GG group(P ＜ 0. 05). Conclusion: Periodontal disease may lead to preterm birth in pregnant women.