Do polyphenol-rich solutions derived from tropical fruit seeds protect dentin against erosive–abrasive challenges?

Objectives To evaluate the effect of polyphenol-rich hydroalcoholic extracts derived from the seeds of four tropical fruits— Paullinia cupana (guaraná), Euterpe oleracea (açaí), Byrsonima crassifolia (murici), and Bactris gasipaes (peach palm)—on dentin under erosive–abrasive conditions. Materials and methods Seed-derived hydroalcoholic extracts were prepared and chemically characterized in terms of total polyphenol content and antioxidant capacity using DPPH and ABTS assays. Human dentin specimens ( n = 180) were subjected to an initial erosive challenge and randomly allocated into six experimental groups ( n = 30). Treatments were applied prior to a 7-day erosive–abrasive cycling model. Dentin surface loss (dSL), collagen degradation (dCol), and calcium release (CaR) were quantitatively assessed, and surface morphology was qualitatively evaluated using scanning electron microscopy (SEM). Data were analyzed using one-way ANOVA followed by Tukey’s test (α = 0.05). Exploratory linear regression analyses were performed to assess the association between total polyphenol content and dentin outcomes. Results P. cupana and E. oleracea exhibited the highest polyphenol content and antioxidant capacity and were associated with significantly reduced dSL, dCol, and CaR compared with the untreated control ( p < 0.05). Qualitative analysis suggested a more compact surface with reduced dentinal tubule exposure in these groups. B. crassifolia demonstrated moderate protective effects, whereas B. gasipaes showed limited efficacy. Exploratory regression analyses indicated a negative association between total polyphenol content and dentin outcomes. Conclusions Polyphenol-rich extracts derived from tropical fruit seeds—particularly P. cupana and E. oleracea —were associated with protective effects on dentin under erosive–abrasive conditions, reducing mineral loss and collagen degradation. However, the underlying mechanisms remain unclear and should be further investigated in future studies. Clinical significance Plant-derived polyphenol-rich extracts may represent a promising adjunctive approach in preventive strategies for erosive tooth wear.