Abstract
Since it is considered that caries susceptibility depends on enamel maturation such as mineralization, cristallization or decrease of organic substances in the tooth enamel, studies were conducted to discover the mechanisms of the posteruptive maturation. As the first step, changes and interrelationships among representative mineral (Ca, P. CO3, and F) concentration, crystallinity and organic components in bovine teeth enamel were examined.
The following results were obtained:
1. During the stage of amelogenesis, great increases of calcium and phosphorus concentrations in the enamel powder were observed, while carbonate, fluoride and organic substances showed a marked decrease in the same specimen. The crystallinity of hydroxyapatite, crystal growth in the a-axis direction increased but in the caxis direction was almost complete, at that time.
2. In the early stage of root formation, the concentrations of calcium and phosphorus were still increasing. However, the rates of their increase in this stage were lower than in the stage of amelogenesis. Also, there was no change in the concentrations of carbonate and fluoride. The crystal growth in the a-axis direction or the decrease of organic substances in the enamel powder was found to he at the same rate as in the first stage.
3. In the late stage of root formation, there was no change in the concentrations of the constituents and the crystal growth.
4. During the stage of tooth eruption, concentrations of calcium and phosphorus increased while those of the carbonate and organic substances decreased. Both of those changes were less than in the stage of amelogenesis.
