Fosfato de cálcio amorfo associado a dois análogos biomiméticos na remineralização de dentina erodida In vitro

Abstract

Biomimetic remineralizationis one of the strategies that seekto mitigate the consequencesof tooth wear by the deposition of minerals similar to hydroxyapatite. Considering the various benefits already established in the literature regarding biomimetic remineralization of initial caries lesions, this study set out to investigate whether the same benefits are relevant to situations involving erosive lesions, whether or not associated with abrasion. Then60 dentin blocks were selected by standardizing the surface microhardness of the specimens and randomly distributed into six groups (n=10), of which three were subjected to erosive cycling (experiment 1) and the others to erosive/abrasive cycling (experiment 2). To simulate erosion, specimens were immersed in 1% citric acid (pH 2.13) for 5 minutes, then in artificial saliva for 1 hour, then in therespective treatment solution for 5 minutesfor 5 days 3 timesaday.In experiment 2, we performed all the previous steps plus mechanical brushing (150 movements)after applying the treatment. The treatments applied were: distilled water (negative control), experimental biomimetic remineralizing solution based on amorphous calcium phosphate, aspartic acid and polyacrylic acid (ACP-ASP-PAA) (investigated treatment, pH 7.6) and 500mM stannous fluoride (positive control, pH 2.69). Thenprofilometry was performed and the data obtained were statistically analyzed by one-way Anova followed by Tukey's post-test, adopting a significance of 5%. Furthermore, superficial dentin morphology was evaluated using Scanning Electron Microscopy (n=2). In experiment 1, the greatest dentin wear was observed in the group treated with distilled waterfollowed by investigated treatmentand the positive control, all different from each other (p<0.05). In experiment 2, the ACP-ASP-PAAtreated group showed no difference in relation to the negative control (p=0.721). Morphologically, the deposition of a significant protective layer was observed in the group treated with stannous fluoride in experiment 1,for experiment 2 the greatest surface deposition was observed in the group treatedwith ACP-ASP-PAA. Therefore, it is concluded that the ACP-ASP-PAAexperimental solution was able to reduce erosive wear, but did not maintain its effect when erosion/abrasion was associated.