In vitro assessment of an experimental coat applied over fluoride varnishes

Abstract

Objective:The time of contact between the product and enamel surface is important in ensuring the efficacy of fluoride varnishes. Thus, some alternatives could avoid fluoride loss to saliva and improve the anticariogenic action of the product. This study evaluated the effect of an experimental coat on the anticariogenic action of fluoride varnishes.Material and Methods:Enamel bovine blocks were selected by evaluating surface microhardness and randomized into five groups (n=24): placebo, Duraphat™, Duraphat™ with coat, Duofluorid™ and Duofluorid™ with coat. Twelve blocks from each group were used to analyze calcium fluoride (CaF2) formed on enamel after treatment. The other 12 blocks were subjected to pH cycling for 7 days. The varnishes were kept on enamel for 6 h. Next, the percentage change of surface microhardness (%SMHC) and mineral loss (ΔZ) were calculated. CaF2 retained and fluoride present in the pH-cycled solutions were also measured.Results:The use of the coat did not decrease %SMHC and ΔZ, but all fluoride varnishes had better results when compared to the placebo (ANOVA and Kruskal-Wallis, respectively). The values from CaF2 formed were higher compared to the values of CaF2 retained (non-paired t test, p<0.05). There was a trend to decrease the amount of F in the solutions at the end of pH cycling (Kruskal-Wallis, p<0.05).Conclusions:Although the experimental coat increased the formation of CaF2 on the enamel surface, it did not significantly improve the anticariogenic action of fluoride varnishes.

Differences in loosely bound fluoride formation and anticaries effect of resin‐based fluoride varnishes

“…There was no correlation between increasing concentrations of loosely bound fluoride and reduced mineral loss, however. The dose–response relationship is absent in the preventive mechanism of carious lesions with the use of fluoride varnishes 5 , and even double the amount of CaF 2 ‐like deposition has not been shown to alter mineral loss 8 . Even showing similar deposition of calcium fluoride, the anticaries effect of Topic Gel group was lower when compared to some of the varnish tested.…”

“…The large amount of fluoride, however, released into the environment could be due to the poor capacity of the Duofluorid and Bifluorid varnishes to retain fluoride in their matrixes caused by differences in their chemical composition, viscosity, density, and synthetic resin base 5,21 . A layer of synthetic resin base (without fluoride) applied over Duofluorid reduces the release to a third of the original value 8 .…”

“…Next, the blocks were immersed in demineralizing (3 h; Ca and P 2.0 m m in acetate buffer, 0.075 m ; 0.04 μg F/mL in pH 4.7, 2.2 mL/mm 2 ) and remineralizing (21 h; Ca, 1.5 m m ; P, 0.9 m m ; KCl, 0.15 m ; cacodylate buffer, 0.02 m ; 0.05 μg F/mL in pH 7.0, 1.1 mL/mm 2 ) solutions. During the pH cycling, the varnishes were removed after 6 h of contact with the tooth enamel surface using a scalpel blade number 15 and acetone 7–9 . The blocks were washed with distilled/deionized water jets for 30 s after removal of the DE–RE solutions.…”

“…The fluoride content of the enamel was determined 24 h after the application of the products that were tested as loosely bound fluoride (CaF 2 ‐like) 8,13 and firmly bound fluoride (FA‐like) 14,15 . A digital caliper (Mitutoyo CD‐15B; Mitutoyo Corporation, Kawasaki City, Kanagawa Prefecture Kawasaki, Japan) was used to measure the surface area of the enamel.…”

Assessment of Enamel Surface Microhardness with different Fluoride Varnishes–An In Vitro Study

“…The study by Attin et al 18 showed that fluoride is released from Duraphat™ topical application during the experimental period. From the study conducted by Delbem et al 19 showed that the retained CaF 2 was higher than formed CaF 2 in the placebo groups. The pH cycling model had a high acid challenge, attributed to use in the present study.…”