Effects of a structural change in collagen upon binding to conditioned dentin studied by 13C NMR

To develop a better adhesive functional monomer, it is imperative to understand the adhesion mechanisms of the resin to the dentin surface. Bond strength to the decalcified dentin surface pretreated with dentin primer, an aqueous ethanol solution of N-methacryloyl glycine, increases by increasing the water content in the primer. The aqueous primer could increase the thickness of the hybrid layer. The structural change of dentinal collagen with NM alpha A was studied by using a model compound for collagen,--(1Pro-2Pro-3Gly)10--, by 13C nuclear magnetic resonance (NMR). The model compound was aggregated in ethanol but dissociated in water. It was found that NM alpha A effectively dissociated the aggregated model compound in water. The dissociation of decalcified dentin was essential to create a thick hybrid layer that could afford a higher bond strength to dentin.