Anti-erosive effect of solutions containing different polymers

Abstract

The prevalence of dental erosion has increased over the last few years, mainly due to changes in dietary and behavioral habits of populations in general. Considering the irreversible nature of this condition, the early diagnosis and the adoption of preventive and therapeutic measures are very important. Recently, the ability of organic and inorganic polymers in reducing dental erosion has been evaluated. The anti-erosive potential of the polymers is due to their compatibility with the dental structures and capacity to form a protective film. This study investigates the effectiveness of addition of polymers to solutions simulating mouthrinses, as well as the effect of the association of these with sodium fluoride (NaF) and NaF associated with stannous chloride (NaF + Sn), in order to protect the dental structures against erosive challenges. In Phase 1, hydroxyapatite crystals will be pre-treated with solutions containing NaF, NaF + SnCl, chitosan, polymethacrylate, polyethylene oxide, hydroxypropyl methylcellulose, pectin and some combination thereof. Deionized water will be used as the control. The pH stabilization method (pH-stat) will be used to evaluate hydroxyapatite dissolution. In Phase 2, the most promising solutions will be tested in an erosion-remineralization cycling model with two treatments per day, for five days, using specimens of bovine enamel. The acid challenge will be performed using citric acid 0.3% (natural pH = 2.6), four times per day. The initial erosion will be evaluated on the first day of cycling by superficial microhardness, and tissue loss will be evaluated after the end of the cycling by contact profilometry. Additional analyses will be done in order to evaluate the alterations in contact angle of enamel (goniometry) and in zeta potential of dispersed hydroxiapatite promoted by the solutions. Data will be analyzed according to the appropriate statistics. (AU)