Pre-eruptive vs. Post-eruptive Fluoride

At the time of tooth eruption, enamel is not quite completely mineralized and will undergo what is now called the post-eruptive period (topical effect) that will take approximately two years.  Throughout this enamel maturation period, fluoride continues to accumulate in the outer surfaces of the enamel.  This fluoride is derived from the saliva, as well as exposure to fluoride-containing products such as food and beverages.  Most of the fluoride incorporated into the developing enamel occurs during what is now called the pre-eruptive (systemic effect) period of enamel formation, but also occurs topically during the post-eruptive period of enamel maturation.