铍对口腔链球菌生长及粘附性能的影响

目的 研究铍离子(Be2+)对口腔链球菌的生长及粘附性能的影响,探讨口腔修复治疗后牙周损伤的微生物机制.方法 含有不同浓度Be2+(5、10、20和40 mg/L)的培养液厌氧培养口腔链球菌24h.检测不同浓 度Be2作用后细菌形态和菌落形成单位(CFU),以及口腔链球菌在唾液包被羟基磷灰石微粒表面的粘附抑制率.结果 铍离子作用后口腔链球菌长链缩短,菌体出现集结趋势.20 mg/L时,菌体表面出现“触角样”变化.随Be2+浓度增加,CFU值减小(P＜0.05),口腔链球菌生长抑制.各实验组口腔链球菌粘附抑制率高于阳性对照组(P＜0.05),但各Be2+浓度组之间粘附抑制率差异无统计学意义(P＞0.05).结论 铍离子抑制口腔链球菌的生长和在牙面的粘附,可能会导致修复体周围正常微生态环境失衡,引起牙周疾病.提示临床应尽量选用理化性能稳定的修复材料.

Effects of beryllium on proliferation and adhesion property of Streptococcus oralis

Objective To evaluate the effects of beryllium on proliferation and adhesive behavior of Streptococcus oralis （S. oralis）, thus explore the microbiologic mechanisms of periodontal diseases which may occur after prosthodontic treatment. Method BeSO4 · 4H2O was added into the liquid culture containing S. oralis. The concentrations of berylliuna ion in the cultures were 5 mg/L, 10 mg/L, 20 mg/L and 40 mg/L, respectively. After 24 hours＇cultivation, cloning forming units （CFU） of S. oralis were determined, and morphology of bacteria was observed using a Scanning electron microscope. Adhesion of S. oralis on the surface of saliva-coated hydroxyapatite microparticles was evaluated using a liquid scintillation technique. Result When Beryllium ion concentration was 5 mg/L or above, the morphology of S. oralis was still ovid as normal, but the chain of bacteria became shorter; At the concentration of 20 mg/L, antenniform change occurred on the surface of S. oralis. The CFU decreased in all the beryllium ion treated groups, and had a dose-effect relationship with the concentration of Be^2＋ （ P 〈 0.05）. The bacteria adhered to the hydroxyapatite microparticles＇ surface decreased in all beryllium treated groups compared with control group （ P 〈 0. 05 ）, but there were no difference among beryllium treated groups （P 〉 0.05）. Conclusion Beryllium＇ can inhibit the proliferation and adhesive behavior of S. oralis, which may result in disturbance in microecologie balance of subgingival microbes after prosthodontic treatments and eventually contribute to periodontal diseases.