含单氟磷酸钠牙膏的pH值变化对釉质再矿化的影响

目的:通过体外实验研究牙膏pH值对釉质再矿化的影响。方法:在40颗无龋前磨牙上均留一3 mm×4 mm窗口,置于pH4.9的凝胶中,40颗牙分8组,每组5颗,窗口下面部分涂清漆作为对照,各组分别置于pH为4.0、4.5、5.1、6.9的含单氟磷酸钠(1.4‰)的牙膏和pH为4.2、4.6、5.3、7.1的无氟牙膏中。连续切片后偏光显微镜观察,EDX进行元素定量分析。结果:pH 4.5和5.1的含氟牙膏孵育的病变体部孔隙减少。其余组实验窗和对照窗无明显差异。元素定量分析显示元素含量各组无差异。结论:pH值略小的含氟牙膏对釉质再矿化有积极作用。

pH variation of toothpastes containing sodium monofluorophosphate on enamel remineralization

Objective： To investigate the effect of different pH levels on enamel remineralization in an in vitro experiment. Methods ： A 3 mm × 4 mm window on the enamel surface of 40 caries free extracted human premolars was demineralized in a hydroxyethyleellulose solution at pH 4.9. The teeth were divided into 8 groups （ n = 5 for each） and the lower half of the window was covered with varnish serving as control, and the tooth in each group was then immersed in toothpaste slurry containing sodium monofluorophosphate （1.4%0） at pH 4.0, 4.5, 5.1 and 6.9 or control toothpaste slurry without fluoride at pH 4.2, 4, 6, 5.3 and 7.1. Serial sections were cut through the lesions and examined with polarization light microscopy （PLM） and quantitative energy dispersive X-ray analysis （EDX）, Results ：The PLM results showed a decreased porous volume of the body of the lesion after incubation with fluoridated toothpaste at pH 4, 5 and 5.1. No differences were found concerning the experimental windows and the windows of the controls in the remaining groups. EDX revealed no differences in each group regarding the element content. Conclusion ： Acidified fluoridated dentifrices with relatively lower pH value may produce certain positive effects on enamel remineralization.