硅和氟对人恒前磨牙釉质脱矿影响的体外研究

In vitro study of the effects of silica and fluoride on demineralization of human premolar enamal

目的:评价硅、氟对离体恒前磨牙釉质脱矿的影响。方法:收集123个正畸拔除的恒前磨牙,制备釉质标本,随机分为对照组、1 mg/L硅(Si)组、1 mg/L氟(F)组,每组41个。将3组标本分别置去离子水、1 mg/L硅溶液、1 mg/L氟溶液预处理8 h、取出标本浸泡于酸蚀凝胶中,随后测定脱矿后7个时间点凝胶中的钙溶出量;并用扫描电镜观察24、168 h脱矿釉质表面超微结构变化。结果:不同脱矿时间,Si组钙溶出量与对照组相比无统计学差异(P﹥0.05);F组钙溶出量低于Si组和对照组,有统计学差异(P﹤0.05);扫描电镜观察各组釉质表面随脱矿时间的延长呈现进行性破坏现象,F组表面破坏程度最轻,168 h后3组蜂窝结构底部均见球状沉积物,Si组沉积物数目较F组多。结论:在体外条件下,1 mg/L Si溶液对前磨牙釉质无明显抑制脱矿作用,1 mg/L F溶液则可明显抑制釉质的脱矿。

AIM： To investigate the effects of silica and fluoride on demineralization of human enamel in vitro.METHODS： Extracted human premolars for orthodontic purpose were selected and used for enamel specimen preparation,all specimens were randomly divided into three groups： control group（distilled water）,F group（1mg/L NaF） and Si group（1mg/L Si）.After pre-treatment for 8h with the mentioned solutions respectively,the specimens were demineralized using acid gel at regular time intervals.The calcium contents released into the acid gel at regular time intervals were determined and the morphological changes of these specimens were observed by using scanning electronic microscope（SEM）.RESULTS： Pretreatment with silica had no significant influence on the contents of calcium released into the acid gel,comparing with the control group.The total contents of the released calcium in the control group and the silica group were significantly higher than those in the fluoride group.No obvious morphological differences were observed between the control group and the silica group,but more particles were found on enamel surfaces in the silica group than on those in the other two groups.CONCLUSION： Pre-treatment with silica does not have obvious effect on the demineralization of enamel.Fluoride can inhibit the demineralization of enamel significantly.