Grape Seed Extract Binding to Mineralized vs. Demineralized Dentin

Objectives: Grape seed extract (GSE) has been shown to inhibit endogenous protease activity in dentin. The aims of this study were to compare the binding capacity of GSE to mineralized versus demineralized dentin powder as function of concentration and to determine how much debinding would result from rinsing with water, 4N GuanidinHCl, 4N Urea or 0.5M NaCl in water.
Methods: Dentin powder was prepared from coronal dentin of extracted human third molars and was mixed with different concentrations of GSE (w/v 1%-10 %) solutions for 30 min at 37°C. After centrifuging the tubes, the supernatant was removed and analyzed for GSE by UV-spectroscopy at 225 nm. After GSE binding, the powders were resuspended in water, 0.5 M NaCl in water, 4N GuanidinHCl or 4N Urea to determine if these solvents could debind GSE. Data were analyzed by using ANOVA and Tukey HSD tests (p=0.05).
Results: Binding of GSE to demineralized dentin was significantly higher compared to mineralized dentin (p<0.05) with the exception of 1% GSE which showed similar binding for both. The GSE binding to mineralized and demineralized dentin powder increased significantly with increasing GSE concentration (p<0.05). Debinding of GSE was both in the order: NaClConclusions: The results suggest that at high concentrations GSE binds anionic dentin by hydrogen bonding and resists the action of rinsing and solvents during bonded protocols.