Influence of Acquired Pellicle on AmF/NaF/SnCl_² Solution Ability in Preventing Enamel Erosion

Objectives: This in situ study evaluated whether the protective effect promoted by the AmF/NaF/SnCl₂ solution in dental erosion would be influenced by presence of acquired pellicle or moment of solution’s application.
Methods: The study was conducted with 12 volunteers, a 3-phase (5 days each) randomized, crossover model. Six treatment protocols were tested using human enamel samples in replicas (n=12): G1 - without treatment, with presence of acquired pellicle; G2 - without treatment, without acquired pellicle; G3 - Rinse with AmF/NaF/SnCl₂ solution prior to the first daily acid immersion, with presence of acquired pellicle; G4 - Rinse with AmF/NaF/SnCl₂ solution prior to the first daily acid immersion, without presence of acquired pellicle; G5 - Rinse with AmF/NaF/SnCl₂ solution after the first daily acid immersion, with the presence of acquired pellicle; G6 - Rinse with AmF/NaF/SnCl₂ solution after the first daily acid immersion, without acquired pellicle. Erosive challenges (1.0% citric acid, pH 2.6, 4x5 min/day and 1.5h interval between immersions) and removal of the acquired pellicle (2% Sodium Dodecyl Sulfate) were performed extra-orally, AmF/NaF/SnCl₂ solution applied via intraoral rinsing (30 sec). Tissue loss were determined by optical profilometry analysis (n=12).
Results: Data were statistically analysed by Two-way ANOVA for randomized blocks, with subsequent pairwise comparison of treatments by Tukey (p<0.05). Results showed that there was no significant interaction between the independent variables “Type of Treatment” and “Acquired Pellicle” (p=0.211). Statistically significant effect of the main factor Type of Treatment (p<0.001) was observed. When compared to the control group (without treatment), enamel wear was significantly lower with application of the AmF/NaF/SnCl₂ solution, regardless of whether it was applied either before or after the erosive challenge, whether in the presence or absence of pellicle.
Conclusions: Therefore, neither the presence of an acquired film, nor the moment of application, influences the effectiveness of the AmF/NaF/SnCl₂ solution against dental erosion.