Fluoride varnishes with calcium glycerophosphate: fluoride release and effect on in vitro enamel demineralization

Abstract

The aims of this study were (1) to assess the amount of fluoride(F) released from varnishes containing calcium glycerophosphate(CaGP) and (2) to assess the effect of the experimental varnishes onin vitro demineralization. Six test groups using 5 varnishes: basevarnish (no active ingredients); Duraphat® ( 2.26% NaF); D uofluorid®(5.63% NaF/CaF2); experimental varnish 1 (1% CaGP/5.63% NaF/CaF2);experimental varnish 2 (5% CaGP/5.63% NaF/CaF2); and no varnishwere set up. In stage 1, 60 acrylic blocks were randomly distributedinto 6 groups (n = 10). Then 300 μg of each varnish was applied toeach block. The blocks were immersed in deionized water, whichwas changed after 1, 8, 12, 24, 48 and 72 hours. Fluoride concentrationin the water was analyzed using a fluoride electrode. In stage 2, 60bovine enamel samples were distributed into 6 groups (n = 10), andtreated with 300 μg of the respective varnish. After 6 h the varnishwas removed and the samples were subjected to a 7-day in vitro pHcycle (6 h demineralization/18 h remineralization per day). Thedemineralization was measured using surface hardness. The resultsshowed that both experimental varnishes released more fluoride thanDuofluorid® and Duraphat® (p < 0.05), but Duraphat® showed thebest preventive effect by decreasing enamel hardness loss (p < 0.05).Therefore, we conclude that even though (1) the experimentalvarnishes containing CaGP released greater amounts of F, (2) they didnot increase in the preventive effect against enamel demineralization