变形链球菌耐氟菌株脱矿能力的体外研究

A study on demineralization of enamel by fluoride-resistant strains of streptococcus mutans in vitro

目的 :探讨变形链球菌耐氟突变后 ,其致釉质片脱矿能力的改变。方法 :采用原子吸收分光光度计 ,测定不同氟浓度条件下变形链球菌耐氟菌株培养物上清液中钙离子浓度 ,并与亲代菌株进行比较。结果 :耐氟菌株脱矿量在无氟化物存在时 ,小于亲代菌株 ;而当 0 .5mmol/L氟离子存在情况下 ,其脱矿量大于亲代菌株。差异具显著性。结论

AIM: To find out the enamel demineralization of S. mutans after fluoride-resistant mutation in vitro . METHODS: The calcium and phosphorus in the supernate of F-resistant and F-sensitive S.mutans media were measured by atomic absorbance spectrophotometer in the presence of 0, 0.05,or 0.5mmol/L NaF。 RESULTS: The fluoride-resistant strains demineralized enamel less than did their parent, wild-type strains when on fluoride existed; whereas the result was opposite in the presence of 0.5mmol/L F. CONCLUSION: The emergence of fluorid-resistant strains will enhance the cariogenicity of S. mutans