The Evalution Of Different Concentration Fluoride Influencing Enamel Of Dental Fluorosis

Objective: To study the effect of different concentrations of fluoride on dental enamel hardness values and surface microstructure,to provide guidance for dental fluorosis patients whether they can use fluoride toothpaste. Methods:Collected 56 clinical extraction moderate fluorosis teeth, divided crown into three equal part, as A group、B group and C group. A group were placed in distilled water, B group were placed in the low concentration fluoride solution(Distilled water 60mg/L, sodium fluoride solution), C group were placed in the high concentration fluoride solution(Distilled water 120mg/L, sodium fluoride solution). Three groups of soaking solution were changed 1 time every day,and 37°C oven for 10 days. Use microhardness and scan electron micrography respectively determinate the changes in enamel surface hardness and enamel surface micro morphology of three groups before and after immersion. Results: The enamel microhardness was of no significant difference between the three groups before immersion(P>0.05), after soaking, the enamel microhardness of B group was highest, higher than that of A group and C group(P<0.01), and enamel microhardness of group A was higher than that of group C(P<0.01). The enamel microhardness of group A before and after soaking was of no significant difference(P>0.05), and the enamel microhardness of B group after soaking was significantly increased than before soaking(P<0.01), and in group C after soaking the enamel microhardness was significantly reduced than before soaking(P<0.01). Scan electron micrography picture showed, in A group and C group enamel surface had no reaction deposits, enamel surface of B group had reaction deposits. Conclusion: High concentration fluoride solution can increase dental fluorosis patients’ decrease of enamel hardness and unable remineralization enamel. Dental fluorosis patients are more suitable to use low concentration fluoride toothpaste brushing.