氟离子导入对乳牙釉质氟分布的影响

Effect on fluoride distribution in enamel of deciduous teeth after iontophoresis

目的应用离子导入技术将氟离子导入乳牙釉质,观察氟离子导入后乳牙釉质氟分布及含量的变化,为进一步开展局部氟化物应用技术预防乳牙龋病提供实验基础。方法收集40例无龋下颌乳中切牙分为两组,每组20例样本都沿唇舌向正中切开,第一组样本分为正常和对照组,第二组样本分为正常与实验组,应用2%氟化钠溶液浸润对照组样本,并同时用离子导入仪对实验组样本进行2%氟化钠溶液离子导入。自釉质表面向内部每10μm定点,利用电子探针检测仪检测釉质表层,直至釉质内部200μm,比较三组氟在乳牙釉质表层的分布变化并进行统计分析。结果电子探针分析显示对照组与实验组釉质表层下均可见氟含量增高,而实验组样本在釉质表层150μm内增高明显(P<0.05),尤其在表层下80～140μm内与对照组相比存在显著差异(P<0.05)。结论正常乳牙釉质氟含量由表及里呈现递减趋势,而氟离子导入能直接、有效地增加乳牙釉质表层的氟含量和渗透深度。

Objective To observe the alterations of fluoride content and distribution in enamel of deciduous teeth after fluoride iontophoresis by pulsed direct current, and to supply the evidence for further research of topical fluoride application technique in caries prophylaxis of deciduous teeth, Methods Forty caries - free lower deciduous central incisors were selected and divided into two groups. In the first group, 20 samples were sectioned into two equal parts longitudinally from buccal side to lingual side as normal and control group, In the second group, the other 20 samples were also sectioned as normal and experimental group. The samples in control group were soaked in 2% NaF solution and the samples in experimental group were treated with iontophoresis using 2% NaF solution at the same time, The alterations of fluoride distribution in the enamel were observed by electron probe micro - analysis, and the values of three groups were statistically analyzed by SPSS software. Results The area with high concentration of fluoride in control and experimental group was observed in map analysis of EPMA. Contrast to the normal group, fluoride contents rose significantly after iontophoresis within the extent of 150μm under the enamel surface （ P 〈 0.05 ）, and especially during 80μm and 140μm, there was significant differences between control and experimental group. Conclusion Iontophoresis technique could increase the fluoride contents and infiltration in superficial enamel of deciduous teeth effectively and directly, but more detailed studies are needed to investigate relative technique parameters.