title: Adhesion mechanisms of resin to etched dentin primed with N-methacryloyl glycine studied by 13C-NMR.
abstract: The origin of the pH-dependent bond strength of the resin to etched dentin treated with N-methacryloyl glycine (NMGly) primer was studied by 13C-nuclear magnetic resonance (NMR) including spin-lattice relaxation time, T1, observation. When the dentinal collagen was suspended in the NMGly solution at pH = 1.6, the T1 values of all the carbons attributed to the NMGly species were significantly decreased. This indicated the presence of an interaction between the NMGly and the dentinal collagen. To obtain detailed information of this interaction, the 13C-NMR spectra of the NMGly were measured in the presence of the model compound for the collagen, (Pro-Pro-Gly)5 at pH = 1.7. The 13C-NMR peaks of the carbonyl carbons of the amide and carboxylic acid in the NMGly species shifted to a higher field and the T1 values decreased. Furthermore, when the molar ratio of (Pro-Pro-Gly)5 to NMGly was decreased from 1:1 to 1:3, the T1 values of the carbonyl carbon attributed to the carboxylic acid in the C-terminal Gly residue of the oligopeptide decreased dramatically. It can be construed that this indicated the formation of a hydrogen bond between the amide, -NH and the carboxylic acid of the NMGly species and the carboxylic acid of the C-terminal Gly residue of the oligopeptide.
authors.affiliation: Department of Dental Materials, Nihon University School of Dentistry at Matsudo, Chiba, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Nishiyama
authors.forename: T
authors.initials: T
authors.lastname: Asakura
authors.forename: K
authors.initials: K
authors.lastname: Suzuki
authors.forename: T
authors.initials: T
authors.lastname: Sato
authors.forename: K
authors.initials: K
authors.lastname: Nemoto
mesh_terms: D000134:Acid Etching, Dental; D000268:Adhesiveness; D002247:Carbon Isotopes; D017220:Dentin-Bonding Agents / Q000737:chemistry*; D005998:Glycine / Q000031:analogs & derivatives* / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008689:Methacrylates / Q000737:chemistry*; D009842:Oligopeptides / Q000737:chemistry; D019279:Resin Cements / Q000737:chemistry*
chemical_list: D002247:Carbon Isotopes; D017220:Dentin-Bonding Agents; D008689:Methacrylates; D009842:Oligopeptides; D019279:Resin Cements; C044555:prolyl-prolyl-glycine; C093041:N-methacryloyl glycine; D005998:Glycine