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

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 on in vitrodemineralization. Six test groups using 5 varnishes: base varnish (no active ingredients); Duraphat® (2.26% NaF); Duofluorid® (5.63% NaF/CaF2); experimental varnish 1 (1% CaGP/5.63% NaF/CaF2); experimental varnish 2 (5% CaGP/5.63% NaF/CaF2); and no varnish were set up. In stage 1, 60 acrylic blocks were randomly distributed into 6 groups (n = 10). Then 300 µg of each varnish was applied to each block. The blocks were immersed in deionized water, which was changed after 1, 8, 12, 24, 48 and 72 hours. Fluoride concentration in the water was analyzed using a fluoride electrode. In stage 2, 60 bovine enamel samples were distributed into 6 groups (n = 10), and treated with 300 µg of the respective varnish. After 6 h the varnish was removed and the samples were subjected to a 7-day in vitro pH cycle (6 h demineralization/18 h remineralization per day). The demineralization was measured using surface hardness. The results showed that both experimental varnishes released more fluoride than Duofluorid® and Duraphat® (p本研究的目标分为两点：（1）评估添加甘油磷酸钙（calcium glycerophosphate, CaGP）的护漆（varnish）释放的氟（F）含量；（2）探讨该实验性护漆对体外脱矿（demineralization）的影响。本研究共设置6个实验组，涵盖5种护漆：空白基质护漆（无活性成分）、Duraphat®（含2.26%氟化钠）、Duofluorid®（含5.63%氟化钠/氟化钙）、实验护漆1（含1%甘油磷酸钙/5.63%氟化钠/氟化钙）、实验护漆2（含5%甘油磷酸钙/5.63%氟化钠/氟化钙），以及无护漆对照组。第一阶段：将60块丙烯酸树脂块随机分为6组，每组10个样本。随后向每块树脂块涂布300 μg的对应护漆，将树脂块浸没于去离子水中，并分别于1、8、12、24、48和72小时更换浸液。采用氟离子电极检测浸液中的氟离子浓度。第二阶段：将60份牛牙釉质样本随机分为6组，每组10个，分别涂布300 μg的对应护漆。6小时后去除护漆，随后将样本置于为期7天的体外pH循环环境中（每日设置6小时脱矿、18小时再矿化周期）。采用表面硬度法检测脱矿程度。结果显示，两款实验性护漆的氟释放量均高于Duofluorid®与Duraphat®（p