Anti-erosive and anti-abrasive effect of a hybrid film associated or not with sodium fluoride or sodium fluoride and stannous chloride in enamel and dentin

Abstract

The aims of this study are: 1) to formulate a hybrid coating and test its effect against enamel and dentin erosion and erosion-abrasion; 2) to modify the hybrid coating with the addition of fluoride and stannous, encapsulated or not, and thereafter test their effects against erosion and erosion-abrasion. The adhesion of the hybrid film to the dental substrate will be tested. Then, sodium fluoride and sodium fluoride plus tin chloride will be added, directly or encapsulated (nano containers), to the polymeric coating. The amounts of fluoride and stannous chloride released from the nano containers on acidic solution will be evaluated by F- selective electrode and atomic emission spectrometry, respectively. The surface morphology of the coatings will be qualitatively analyzed using scanning electron microscopy. Then, enamel and dentin specimens obtained from bovine incisors will be treated with the polymeric coatings and tested in an erosion or erosion-abrasion cycling model (n = 10 for each substrate, for each cycling). Deionized water will be used as a negative control. The erosive cycling will consist of 5 min immersion in 0.3% citric acid (pH 2.6), followed by 60 min exposure to artificial saliva. This procedure will be repeated 4 times a day, for 5 days. For the erosion-abrasion cycling, the same protocol will be followed, however, the specimens will be brushed in a brushing machine, after the first and last erosive challenge, with a dentifrice slurry (1:3), for 15 s (total of 2 min exposure to the slurry). At the end of the experiment, surface loss (in µm) will be evaluated with an optical profilometer. Surface loss data will be statistically analyzed using appropriate methods (± = 0.05). (AU)