title: Effects of HEMA/solvent combinations on bond strength to dentin.
abstract: Re-expansion of dried demineralized dentin is required to optimize resin adhesion. This study tested the hypothesis that bond strengths to dentin depend upon the ability of experimental HEMA(2-hydroxy-ethyl-methacrylate)/solvent primers to re-expand the matrix. Dentin surfaces were acid-etched with 37% phosphoric acid for 20 sec, air-dried for 30 sec, primed with either 35/65% (v/v) HEMA/water, HEMA/methanol, HEMA/ethanol, or HEMA/propanol for 60 sec, and bonded with 4-META-TBBO(4-methacryloyloxyethyl trimellitate anhydride-tri-n-butyl borane) adhesive. After storage in water for 1 day at 37 degrees C, the samples were prepared for microtensile bond strength testing. We used transmission electron microscopy to measure the width of interfibrillar spaces in the hybrid layers. The HEMA/ethanol primer and the HEMA/propanol primer produced the highest and the lowest bond strengths, respectively (p < 0.05). Bond strengths were directly correlated with the width of the interfibrillar spaces (p < 0.05). Bond strengths are related to the ability of the primer to maintain the re-expansion of collapsed demineralized dentin matrix.
authors.affiliation: Department of Operative Dentistry, Endodontics and Dental Materials, University of São Paulo, Bauru School of Dentistry, FOB USP, Depto. Dentística, Al. Otávio P. Brisola 9-75, Bauru, SP, 17012-101, Brazil. ricfob@fob.usp.br
authors.forename: R M
authors.initials: RM
authors.lastname: Carvalho
authors.forename: J S
authors.initials: JS
authors.lastname: Mendonça
authors.forename: S L
authors.initials: SL
authors.lastname: Santiago
authors.forename: R R
authors.initials: RR
authors.lastname: Silveira
authors.forename: F C P
authors.initials: FC
authors.lastname: Garcia
authors.forename: F R
authors.initials: FR
authors.lastname: Tay
authors.forename: D H
authors.initials: DH
authors.lastname: Pashley
mesh_terms: D000433:1-Propanol / Q000737:chemistry; D000134:Acid Etching, Dental; D000180:Acrylic Resins / Q000737:chemistry; D001896:Boron Compounds / Q000737:chemistry; D001840:Dental Bonding; D003804:Dentin / Q000648:ultrastructure*; D017220:Dentin-Bonding Agents / Q000737:chemistry*; D000431:Ethanol / Q000737:chemistry; D006801:Humans; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry*; D000432:Methanol / Q000737:chemistry; D010756:Phosphoric Acids / Q000737:chemistry; D012044:Regression Analysis; D012997:Solvents / Q000737:chemistry*; D013499:Surface Properties; D013696:Temperature; D013718:Tensile Strength; D013997:Time Factors; D014867:Water / Q000737:chemistry
chemical_list: D000180:Acrylic Resins; D001896:Boron Compounds; D017220:Dentin-Bonding Agents; D008689:Methacrylates; D010756:Phosphoric Acids; D012997:Solvents; D014867:Water; C009523:tri-n-butylborane; D000431:Ethanol; C005044:hydroxyethyl methacrylate; C031172:4-META resin; D000433:1-Propanol; D000432:Methanol