Substantive Fluoride Release From a New Fluoride Varnish Containing CXP

Objectives: A new fluoride varnish (Embrace, Pulpdent) containing Xylitol-coated Calcium and Phosphate (CXP) claims to release ten times more fluoride over a four hour period than the leading fluoride varnish. The purpose of this study was to evaluate the substantivity of a new fluoride varnish when compared to the quantity and rate of fluoride release from enamel of currently marketed fluoride varnishes.
Methods: Extracted human third molars were cut into 4mm x 4mm sections using twenty tooth sections per group (n=20). The dentin portions of each section were covered with nail polish, leaving only enamel portions exposed. Three milligrams of Embrace, Enamel Pro (Premier), Duraphat (Colgate), or Vanish (3M/ESPE) fluoride varnish was applied to the enamel surface. One group was not treated and served as a negative control. Sections were immersed in 20mL of synthetic saliva (37°C) which was replaced at tested intervals. The concentration of fluoride in ppm (Accumet AR50, Fisher Scientific) was measured after specified hourly intervals during the first week and then weekly until the limit of detection (LOD). See table. Mean cumulative fluoride release and rate of release were analyzed with a one-way ANOVA/Tukey (alpha=0.05).
Results: Significant differences existed between groups (p<0.001). Mean cumulative fluoride release: Embrace > Enamel Pro > Duraphat = Vanish. Rate of fluoride depletion: Embrace > Duraphat = Enamel Pro = Vanish.
Conclusions: Embrace had the greatest initial fluoride initial release, exceeding ten times the release of fluoride compared to a popular varnish (Vanish) in the first four hours; however, Embrace had the highest rate of fluoride depletion and lowest substantivity of all varnishes tested.