Abstract
A new coating agent which adheres to the enamel was developed. Fluoride ion from NaF at various concentrations (10,50,100 ppm F-) was incorporated into the agent. The human premolors were coated with wax exposing two windows, they were immersed in a decalcifying solutions which was prepared in 100mM lactic acid and 17% gelatin gel for three weeks to form artificial white spot lesions. One window was applied with the new coating agent, the other window was free of the new coating agent. The teeth were immersed in calcifying solutions for 10 days. Horizontal ground sections were examined in quinoline using a polarlized microscope. It shows increased in the negative birefrigence on surface area and the advancing front of the lesion. Microbeam x-ray diffraction analysis suggested that fluoridated hydroxyapatite formed in this region and crystallinity increased mostly in the c-axis direction, indicating that crystal growth of fluoridated hydroxyapatite occurred in this direction maintaining the original orientation of enamel. Comparison of the data obtained at various F- concentrations in the agent clearly suggest that 10 ppm F- is the most effective in remineralization of the white spot lesions.
In a clinical study the remineralizing effect of 10 ppm F- containing the coating agent was evaluated on naturally formed white spot lesions of human enamel for three months. Sixteen children, who volunteered for this study, were given instruction to practice good oral hygiene with fluoride free dentifrice. Each child was observed for two month-period. The new coating agent was applied on the first visit, after 1 week,2 weeks, and 1 month later for a total of four times.70% of the teeth showed a reduction of the incidence of white spot lesions and most surprizingly 25% of them disappeared.
Results obtained both in vitro and in vivo clearly suggest that the fluoride containing coating agent has prominant ability to arrest incipient enamel caries and promote remineralization in white spot lesions.
