Effect of experimental dentifrices containing epigallocatechin-3-gallate–loaded chitosan nanoparticles on permeability, tubule occlusion, microhardness, and wear in eroded dentin

<h2>Abstract</h2><h3>Background</h3> Dentin hypersensitivity and tooth wear are common oral conditions. Natural substances and nanotechnology emerge as promising approaches. This study aimed to evaluate the effect of experimental dentifrices containing epigallocatechin-3-gallate (EGCG)–loaded chitosan nanoparticles (NChi) on permeability (Lp), tubule occlusion, microhardness, and wear in dentin under erosive challenge. <h3>Methods</h3> This in situ study included 5 phases (5 days each) and a washout period (7 days). Eight participants wore intraoral mandibular devices containing 2 bovine dentin samples on each side with tubule exposure (time [T]1). The samples were eroded extraorally (0.3% citric acid, pH=2.6, 4 times per day) and intraorally brushed with dentifrices (15 seconds, 2 times per day) for 5 days (T2), according to the following groups: placebo (PL), NChi, EGCG encapsulated in chitosan (NChi and EGCG), EGCG, and Elmex Sensitive (ES) (GABA). Lp, open dentin tubules, surface microhardness (SMH), surface loss, and scanning electron microscopy results were assessed. <h3>Results</h3> All groups showed significant differences in Lp between T1 and T2 (<i>P</i> < .05), and PL was different from the other groups at T2 (<i>P</i> < .05). For both open dentin tubules and SMH, all groups except PL showed statistical differences between T1 and T2 (<i>P</i> < .05). At T2, NChi and EGCG, EGCG, and ES showed higher SMH than PL (<i>P</i> < .05). There was no statistically significant difference among the groups in terms of the surface loss (<i>P</i> = .29). <h3>Conclusions</h3> Dentifrices containing an active composition (NChi, NChi and EGCG, EGCG, ES) were effective in promoting tubule occlusion and increasing microhardness, with comparable efficacy. All the dentifrices showed similar wear on the dentin surface.