Morphological and physicochemical impact of an experimental epigallocatechin-3-gallate based gel on erosive dentin wear.

PURPOSE: The aim of this study is to evaluate in vitro the morphological and physicochemical effects of an experimental epigallocatechin-3-gallate (EGCG) gel and its combination with sodium fluoride (NaF) on the progression of dentin erosion. MATERIALS AND METHODS: Initial lesions were induced in bovine dentin samples (n=10/group) and divided into: Control (gel without active ingredients), NaF (1.23% NaF), EGCG (10% EGCG), and EGCG+NaF (10% EGCG + 1.23% NaF). Half of the sample was protected and the other half treated and subjected to erosive/abrasive challenges (0.3% citric acid, pH=2.6 and simulated brushing). Volume loss (VL) and surface roughness (Ra) were evaluated by 3D laser confocal microscopy. Dentin composition was analyzed by Raman spectroscopy, considering mineral/matrix ratio (MMR), collagen organization, and crystallinity. RESULTS: The EGCG+NaF group presented the lowest VL values (p<0.05). The Control group had the highest MMR values, while the EGCG+NaF group presented the lowest (p<0.05). For the Amide I/III ratio, the Control group had the lowest values and the EGCG+NaF group the highest (p<0.05). No statistically significant differences among the groups regarding the crystallographic order (p= 0.668). CONCLUSION: The combination of EGCG and NaF demonstrates the ability to mitigate volume loss under erosive-abrasive challenges, preserve structural integrity, and enhance collagen cross-linking within the demineralized organic matrix of dentin.