ヒト歯牙エナメル質表層におけるフッ素取込みに関する実験的研究

Abstract

In preventive dentistry the fluoride treatment is used for decreasing the caries susceptibility which depends upon the fluoride contents in the surface enamel. It is necessary to clarify these problems that the susceptibility to the fluoride is related with the post-eruptive maturation of the surface. A window was opened for the control and fluoride application on the surface enamel in each four layers. The volume of the calcium and fluoride between the unerupted (horizontally impacted) teeth and the erupted (lower first molar) teeth was determined. The results of this research were as follows : 1. the calcium content increased along with the inner layers. 2. The fluoride content in each group showed the maximum in the first layer and decreased along with the inner layers. The fluoride concentration in the erupted group was higher than the unerupted group in each layer. 3. The calcium and fluoride contents were in inverse relation. 4. The fluoride concentration in the unerupted and erupted teeth increased more on the outer surface layer than that of the inner layer. 5. The fluoride concentration in each erupted tooth was significantly higher than in the unerupted teeth. 6. The fluoride uptake on the unerupted enamel surface exposed to APF solution was almost the same (100 ppm) in each layer. But, in the erupted teeth, the uptake was more than ten times that in the unerupted teeth at the level 3 μm from the surface and seemed to be similar at levels below 50μm as compared with the unerupted teeth. It was concluded that the post-eruptive maturation progressed in the layer up to 20μm from the enamel surface within which the fluoride exchanges.