Characterization of dentin matrix biomodified by Galla chinensis extract

The aim of this study was to systemically investigate the potential of Galla chinensis extract (GCE) to interact with the dentin matrix to improve its biochemical and biomechanical properties and structural stability.

The fully demineralized dentin matrices were prepared and biomodified by 0.4% and 4% GCE solutions, with 5% glutaraldehyde and distilled deionized water as positive and negative controls, respectively. The GCE-dentin matrix interaction was assessed by Fourier transform infrared spectroscopy. The biomodification effects of GCE on the biochemical, biomechanical, and structural properties were assessed by a series of assays including denaturation temperature, swelling ratio and enzymatic biodegradation rate, elastic modulus, ultimate tensile strength, and transmission electron microscopy.

GCE could interact with dentin matrix through formation of hydrogen bonds. Compared with negative control, the GCE and glutaraldehyde-treated dentin matrix showed significantly higher denaturation temperature, lowered swelling ratio, and reduced biodegradability against enzymatic digestion. GCE treatment significantly increased elastic modulus values of dentin matrix in a concentration- and time-dependent manner. Biomodification by GCE maintained the ultimate tensile strength and structural integrity of dentin matrix after storage in proteolytic conditions.

GCE can stabilize the dentin matrix against thermal and proteolytic challenges, improve its biomechanical properties, and maintain its structural integrity with long duration. The mechanism is probably due to the formation of GCE-dentin matrix complex.