title: Influence of an oxygen-inhibited layer on enamel bonding of dental adhesive systems: surface free-energy perspectives.
abstract: The influence of an oxygen-inhibited layer (OIL) on the shear bond strength (SBS) to enamel and surface free-energy (SFE) of adhesive systems was investigated. The adhesive systems tested were Scotchbond Multipurpose (SM), Clearfil SE Bond (CS), and Scotchbond Universal (SU). Resin composite was bonded to bovine enamel surfaces to determine the SBS, with and without an OIL, of adhesives. The SFE of cured adhesives with and without an OIL were determined by measuring the contact angles of three test liquids. There were no significant differences in the mean SBS of SM and CS specimens with or without an OIL; however, the mean SBS of SU specimens with an OIL was significantly higher than that of SU specimens without an OIL. For all three systems, the mean total SFE (γS), polarity force (γSp), and hydrogen bonding force (γSh) values of cured adhesives with an OIL were significantly higher than those of cured adhesives without an OIL. The results of this study indicate that the presence of an OIL promotes higher SBS of a single-step self-etch adhesive system, but not of a three-step or a two-step self-etch primer system. The SFE values of cured adhesives with an OIL were significantly higher than those without an OIL. The SFE characteristics of the OIL of adhesives differed depending on the type of adhesive.
authors.affiliation: Department of Operative Dentistry, Nihon University School of Dentistry, Tokyo, Japan.
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Ueta
authors.affiliation: Department of Operative Dentistry, Nihon University School of Dentistry, Tokyo, Japan.|Department of General Dentistry, Creighton University School of Dentistry, Omaha, Nebraska, USA.
authors.forename: Akimasa
authors.initials: A
authors.lastname: Tsujimoto
authors.affiliation: Department of General Dentistry, Creighton University School of Dentistry, Omaha, Nebraska, USA.
authors.forename: Wayne W
authors.initials: WW
authors.lastname: Barkmeier
authors.affiliation: Department of Operative Dentistry, Nihon University School of Dentistry, Tokyo, Japan.
authors.forename: Hajime
authors.initials: H
authors.lastname: Oouchi
authors.affiliation: Department of Operative Dentistry, Nihon University School of Dentistry, Tokyo, Japan.
authors.forename: Keiichi
authors.initials: K
authors.lastname: Sai
authors.affiliation: Department of Operative Dentistry, Nihon University School of Dentistry, Tokyo, Japan.
authors.forename: Toshiki
authors.initials: T
authors.lastname: Takamizawa
authors.affiliation: Department of General Dentistry, Creighton University School of Dentistry, Omaha, Nebraska, USA.
authors.forename: Mark A
authors.initials: MA
authors.lastname: Latta
authors.affiliation: Department of Operative Dentistry, Nihon University School of Dentistry, Tokyo, Japan.
authors.forename: Masashi
authors.initials: M
authors.lastname: Miyazaki
mesh_terms: D000134:Acid Etching, Dental; D000818:Animals; D002417:Cattle; D003188:Composite Resins; D001840:Dental Bonding; D003738:Dental Cements; D003743:Dental Enamel; D003799:Dental Stress Analysis; D017220:Dentin-Bonding Agents; D008422:Materials Testing; D010100:Oxygen; D019279:Resin Cements; D033081:Shear Strength
chemical_list: D003188:Composite Resins; D003738:Dental Cements; D017220:Dentin-Bonding Agents; D019279:Resin Cements; D010100:Oxygen
keywords: bond strength; dental adhesive; oxygen-inhibited layer; surface free-energy