Photodynamically crosslinked and chitosan-incorporated dentin collagen

A lingering concern with restored root-filled teeth is the loss of structural integrity of the dentin and dentin-sealer interface over time. we hypothesized that crosslinking of dentin collagen with simultaneous incorporation of a biopolymer into collagen matrix would improve its structural stability. this study aimed to investigate the effects of combining chemical/photodynamic crosslinking of dentin collagen with the incorporation of carboxymethyl-chitosan (cmcs) on the resistance to enzymatic degradation and mechanical properties of dentin collagen. ninety-six demineralized dentin collagen specimens (human,n = 72; and bovine,n = 24) were prepared and crosslinked chemically/ photodynamically,with/without cmcs. glutaraldehyde and carbodiimides were used for chemical crosslinking,while rose bengal activated with a non-coherent light (540 nm) at 20 j/cm2 was applied for photodynamic crosslinking. the crosslinked human dentin collagen was subjected to chemical characterization,7 days enzymatic degradation,and transmission electron microscopy (tem),while the bovine dentin collagen was used for tensile-testing. crosslinked collagen showed significantly higher resistance to enzymatic degradation (p < 0.01),stable ultrastructure,and increased tensile strength (p < 0.05). crosslinking cmcs with collagen matrix as observed in the tem further improved the mechanical properties of dentin collagen (p < 0.01). this study highlighted the possibility of improving the resistance and toughness of dentin collagen by chemically/photodynamically crosslinking collagen matrix with cmcs. © 2011 international & american associations for dental research.