[Effect of beryllium on chemical elements of cell membrane and H2O2 production of Streptococcus oralis].

PURPOSE:To evaluate the effect of beryllium (Be(2+)) on chemical elements of cell membrane and H2O2 production of Streptococcus oralis (S.oralis), thus to explore the microbiologic mechanisms of periodontal diseases which may occur after prosthodontic treatment. METHODS:S.oralis was put into artificial saliva with different Be(2+) concentration (5mg/L, 10mg/L, 20mg/L and 40mg/L) and anaerobic cultured for 24 hours. The amount of chemical elements in the membrane of S.oralis were tested with X-ray energy dispersive spectroscopy, and the H(2)O(2) produced by S.oralis was detected with ABTS-HRP. The data were analyzed with one-way ANOVA using SPSS 11.0 software package. RESULTS:The amount of calcium in the cell membrane of beryllium treated S. oralis decreased, while the amount of phosphorus increased. Natrium increased with the increase of Be(2+) in the culture, but changed contrarily when S. oralis was treated with 20mg/L Be(2+). H(2)O(2) produced by S. oralis reduced when the concentration of Be(2+) was at 40mg/L(P<0.05). CONCLUSIONS:Beryllium affects the amount of chemical elements in cell membrane and H(2)O(2) production of S. oralis, which may result in a disturbance in the microecologic balance of subgingival microbes after proshodontic treatments and eventually contribute to periodontal diseases.