Chemical and morphological analysis of permeable dentin exposed to experimental solutions containing epigallocatechin-3-gallate encapsulated in chitosan nanoparticles

Abstract

Objective

To evaluate the effects of epigallocatechin 3-gallate (EGCG) and chitosan-based solutions on the chemical and morphological structure of permeable dentin using Fourier Transform Infrared Spectroscopy with Attenuated Reflectance Accessory (FTIR-ATR), Energy dispersive X-ray spectroscopy – EDS, and Scanning Electron Microscopy (SEM) analyses.

Design

Bovine root dentin specimens were demineralized with EDTA to simulate dentin hypersensitivity. Specimens were divided into six groups (n = 6): EGCG encapsulated in chitosan nanoparticles (Nchi + EGCG), chitosan nanoparticles (Nchi), EGCG, Elmex Sensitive, deionized water (negative control), and No solution/no acid challenge. Solutions were applied, followed by cycles of citric acid (2 min, 0.3 %, pH 2.45) and artificial saliva (1 h, 4 ×/7 days). Data were analyzed using Kolmogorov-Smirnov, ANOVA, and Tukey’s tests.

Results

FTIR spectra revealed enhanced phosphate, carbonate, and amide bands in Nchi + EGCG, EGCG, Nchi, and Elmex groups. EDS showed no significant differences in Ca/P ratios among treated groups, but Nchi and Nchi + EGCG differed significantly from the No solution/no acid challenge (p < 0.05). There were significant differences in the number of dentinal tubules between the Nchi/Nchi + EGCG and EGCG/No solution applied groups (P < 0.05), but no differences among experimental solutions and negative control (p > 0.05). Nchi + EGCG and EGCG showed the smallest open dentinal tubule areas (P = 0.00 and P = 0.001, respectively).

Conclusion

Nchi + EGCG modified dentin by enhancing collagen interaction; however, it does not alter Ca/P ratio. Solutions containing EGCG (EGCG and Nchi + EGCG) can reduce the open tubule area.