Gel Containing Catechin and Mesoporous Silica Nanoparticles for Protecting Root Dentin Against Erosion: An In Situ Study

This study evaluated the in situ anti-erosive effect of gels containing epigallocatechin-3-gallate (EGCG) isolated and adsorbed on mesoporous silica nanoparticles (EGCG/MSN) on eroded dentin. Eleven volunteers participated in this randomized, controlled, cross-over study, which consisted of 4 phases of 5 days. Acrylic palatal devices were utilized containing two dentin blocks treated with one of the gels: placebo (negative control), SnF₂ (0.05%-positive control), EGCG (0.1%), and EGCG/MSN (0.093%). The specimens were immersed in citric acid (0.05 M; pH 3.75) for 60 s, 4×/day, followed by treatment with the assigned gel for 60 s. The alterations were evaluated by the percentage of surface hardness loss (%SHL) and through profilometry analysis (wear). Morphological changes were assessed using scanning electron microscopy (SEM). The data were analyzed using ANOVA, followed by Tukey's post-test. The %SHL did not show a significant difference among the groups. Regarding surface wear, the mean results in micrometers were: placebo, 0.66 (±0.38); EGCG, 0.57 (±0.11); EGCG/MSN, 0.48 (±0.05); and SnF₂, 0.32 (±0.08). A significant difference was observed between the SnF₂ group and the placebo and EGCG groups. However, there were no difference between the EGCG/MSN group and the control ones. Within the limitations of the study, EGCG/MSN may act as a protective measure in reducing dentin wear under erosive conditions since it did not differ from the positive control.