Apatitic Fluoride Increase in Enamel from a Topical Treatment Involving Intermediate CaHPO4·2H2O Formation, an in vivo Study

Abstract

Previous laboratory and animal studies have reported high levels of apatitic fluoride uptake from a topical fluoride procedure in which teeth were pretreated with an acidic solution saturated with respect to CaHPO₄ • 2H₂O (DCPD) prior to the fluoride treatment. A study was initiated to determine the fluoride uptake from this procedure under clinical conditions. A microbiopsy technique was used to measure enamel fluoride contents before, 1 month after, and 3 months after an application of an acidulated phosphate fluoride (APF) solution alone or in combination with a DCPD pretreatment on the maxillary incisors of 50 fourth-grade children in a nonfluoride area. 1 month after treatment, there was no significant difference in enamel fluoride concentration between APF and control groups. The DCPD/APF treatment produced mean fluoride uptakes of 1,011 ± 134 ppm (n = 50) and 2,042 ± 221 ppm (n = 47) in the outer 3.5 μm of enamel when measured 1 and 3 months, respectively, after treatment. The results indicate that the DCPD pretreatment can substantially increase permanently bound fluoride uptake under clinical conditions.