Changes in Salivary Free Fluoride Ion Concentration after Adding Low-Concentration Fluoride - Abstract
Fluoride (F) is well known to be effective for caries prevention; however, the safest and most effective method of administration is still unclear. Education regarding efficacy and administration of F is necessary for patients, especially for children and their guardians. In this study, we attempted to elucidate the factors that decrease added F in artificial saliva, and the factors that maintain appropriate salivary F ion concentration for cavity protection. Our original rigorous pilot study determined that the baseline salivary F ion concentration in infants was lower than the free F ion concentration required for caries prevention. The present study aimed to determine the major factors that reduced added F in solution. Organic salivary components (the proteins mucin and albumin) and inorganic salivary components (calcium) were applied in this study and the decrease in F ratios was measured after adding low-concentration F. Consequently, the free F ion concentration in F-added protein and calcium solutions showed significantly lower values compared with that in ultrapure water with the same amount of added F. Furthermore, the free F ion concentration in protein plus calcium solution exhibited a greater decrease after adding low-concentration F. This indicated that there is a synergistic action between protein and calcium when binding with added F in solution.