Fluoride Plus Calcium Phosphate Varnishes: A Possible Link between Mineral Phase Formations and Observed Clinical Outcomes

Introduction: Incorporation of calcium phosphate agents into fluoride varnishes might improve anticaries benefits. But when clinical results do not mirror this view, explanations remain unclear. The hypothesis: Our hypothesis is that better clinical outcomes are obtained from fluoride plus calcium phosphate varnishes when there is sustained, controlled release of mineralizing ions. Evaluation of the hypothesis: Calculations of ion activity products and putative mineral phases have been underutilized in assessing clinical outcomes of fluoride varnishes with calcium phosphate agents. In this study, a mineral phase comparison between a low-release varnish comprising functionalized tricalcium phosphate (fTCP) against a high-release varnish comprising casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) was made. These calculations revealed the predominance of hydroxyapatite, fluorapatite, and calcium fluoride formation for the varnish containing fTCP, whereas the varnish containing CPP-ACP produced the same minerals along with β-TCP and octacalcium phosphate. This hypothesis shows the mineral phases expected to form from fluoride plus calcium phosphate varnishes might bear on clinical outcomes.