Anti-erosive effect of fluoride solutions associated with methacrylate polymer: A randomized crossover in situ study

OBJECTIVES: To evaluate the anti-erosive effect of solutions containing fluoride and aminomethacrylate copolymer associations on enamel and dentin, using a randomized crossover in situ model. METHODS: Bovine enamel and dentin specimens were fixed in intraoral devices. Participants (n = 12) installed the devices and rinsed with seven experimental solutions in a randomized sequence, with 2-day washout between them: Ultrapure water-C; Sodium fluoride-F (225 ppmF-); Stannous Chloride-Sn (800 ppm Sn2+); Aminomethacrylate- AA (2 %); FSn; F+AA; FSn+AA. After treatments, they retained the device for acquired pellicle maturation (30 min). Specimens were then extraorally exposed to 0.03 % HCl, pH 2.3 (3 min). This cycling was repeated six times. Calcium released from the acid solutions was measured photometrically, and mineral loss (ML) was calculated. KOHsoluble fluoride (μg/cm2) and surface microhardness (KHNred) were also measured. Data were submitted to RM-ANOVA and Tukey tests (5 %). RESULTS: For mineral loss in enamel, the F+AA and FSn+AA solutions were statistically superior than F and FSn, respectively. In dentin, the F+AA solution showed the best performance (p < 0.001). The KHNred results for the enamel were: C = Sn < AA = F = FSn < F+AA = FSn+AA. The FSn groups exhibited higher concentration of fluoride adsorbed on both enamel and dentin surface (p < 0.05). CONCLUSION: The addition of aminomethacrylate copolymer to fluoride solutions improved their efficacy in protecting the tooth against erosion in the presence of acquired pellicle, being a promising agent to be incorporated in mouthrinses. CLINICAL SIGNIFICANCE: The investigation of the anti-erosive effect of polymers and fluoride provides subsidies for identifying the most promising associations, which open new perspectives for the development of formulations capable of preventing erosion progression to more advanced stages, which requires complex and costly restorative interventions.