Improved biostability of collagen in sound and caries-affected dentin using an integrated crosslinking-remineralization treatment

This study investigated a combined strategy using collagen crosslinking and polymer-induced liquid precursors (PILP)-based remineralization to enhance collagen biostability and resistance to collagenase degradation in sound (SD), denatured (DD), and caries-affected dentin (CAD). Ultra-thin demineralized collagen films and acid-etched dentin beams with demineralized layers (DL) were treated with 1% cranberry-extract (CR) collagen crosslinker for 30 s, followed by PILP remineralization for 1–7 days. Biostability was assessed by collagenase-induced weight loss and hydroxyproline release; structural and remineralization changes were evaluated via electron microscopes. Both CR and PILP individually improved collagen biostability, with greater effects in SD than DD. CR crosslinking was more effective than PILP alone. Notably, the combined CR-PILP approach produced the greatest enhancement in biostability. Electron microscopes confirmed that this dual treatment preserved the DL from enzymatic digestion and dramatically accelerated mineral deposition in both SD and CAD. These findings support the potential of this synergistic strategy for improving dentin restoration durability.