title: Effect of 2-(methacryloxy)ethyl phenyl hydrogen phosphate on adhesion to dentin.
abstract: A variety of methacrylate-based materials has been developed with the capacity of adhering to dentin. This study investigated the effectiveness of 2-(methacryloxy)ethyl phenyl hydrogenphosphate (phenyl-P) for bonding 5% phenyl-P in methyl methacrylate (MMA) to dentinal surfaces. Polymerization of the phenyl-P/MMA monomer was initiated by partially oxidized tri-n-butyl borane catalyst (TBB). The mean tensile bond strength of 5% phenyl-P in MMA to dentin that was pre-treated with an aqueous solution of 10% citric acid/3% ferric chloride, abbreviated as 10-3, was found to be 10.5 MPa. Scanning electron microscope examination demonstrated the formation of a transitional or "hybrid" layer of resin-reinforced dentin, created by the intermingling and entanglement of polymerized resin with collagen bundles exposed by dentin pre-treatment with 10-3, an effective remover of the dentinal smear layer. This "hybrid" layer or zone was essential for high tensile bond strength to be attained. Phenyl-P was found to be effective in promoting monomer diffusion and impregnating monomer into demineralized dentinal surfaces. The formation of the "hybrid" layer of resin-reinforced dentin followed in situ resin polymerization initiated by partially oxidized tri-n-butyl borane (TBB). Ferric (Fe3+) ions deposited on dentinal surfaces from the 10-3 solution also acted to improve monomer diffusion and entanglement with demineralized dentin, and facilitated the formation of the "hybrid" layer/zone.
authors.affiliation: Division of Organic Materials, Tokyo Medical and Dental University, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Wang
authors.forename: N
authors.initials: N
authors.lastname: Nakabayashi
mesh_terms: D000134:Acid Etching, Dental; D000180:Acrylic Resins / Q000737:chemistry; D000269:Adhesives / Q000737:chemistry*; D000818:Animals; D001896:Boron Compounds / Q000737:chemistry; D002417:Cattle; D001840:Dental Bonding; D003799:Dental Stress Analysis; D003804:Dentin / Q000648:ultrastructure; D008768:Methylmethacrylates / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D013499:Surface Properties; D013718:Tensile Strength
chemical_list: D000180:Acrylic Resins; D000269:Adhesives; D001896:Boron Compounds; D008768:Methylmethacrylates; C009523:tri-n-butylborane; C031172:4-META resin