title: Influence of oxygen inhibition on the surface free energy and enamel bond strength of self-etch adhesives.
abstract: We compared the surface free energies and enamel bond strengths of single-step self-etch adhesives with and without an oxygen-inhibited layer. The adhesives were applied to the enamel surfaces of bovine incisors, light irradiated, and the oxygen-inhibited layer was either retained or removed with ethanol. The surface free energies and their components (γ(S)(LW), γ(S)(+), and γ(S)(-)) were determined by measuring the contact angles of three test liquids placed on the cured adhesives. The enamel bond strengths of specimens with and without the oxygen-inhibited layer were measured. For all surfaces, the value of the estimated surface tension component γ(S)(LW) was relatively constant. The value of the γ(S)(+) component increased slightly when the oxygen-inhibited layer was removed, whereas that of the γ(S)(-) component decreased significantly. The enamel bond strengths of the self-etch adhesives were significantly lower in the specimens without an oxygen-inhibited layer. The oxygen-inhibited layer therefore appeared to promote higher enamel bond strength.
authors.affiliation: Department of Operative Dentistry, Nihon University School of Dentistry, 1-8-13, Kanda-Surugadai, Chiyoda-ku, Tokyo 101-8310, Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Oyama
authors.forename: Akimasa
authors.initials: A
authors.lastname: Tsujimoto
authors.forename: Eiichiro
authors.initials: E
authors.lastname: Otsuka
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Shimizu
authors.forename: Koji
authors.initials: K
authors.lastname: Shiratsuchi
authors.forename: Keishi
authors.initials: K
authors.lastname: Tsubota
authors.forename: Toshiki
authors.initials: T
authors.lastname: Takamizawa
authors.forename: Masashi
authors.initials: M
authors.lastname: Miyazaki
mesh_terms: D000818:Animals; D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry; D002417:Cattle; D001840:Dental Bonding / Q000379:methods*; D003738:Dental Cements / Q000737:chemistry*; D003743:Dental Enamel / Q000648:ultrastructure*; D000431:Ethanol / Q000737:chemistry; D019855:Ethylene Glycol / Q000737:chemistry; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry; D009281:Naphthalenes / Q000737:chemistry; D010100:Oxygen / Q000737:chemistry*; D011092:Polyethylene Glycols / Q000737:chemistry; D011109:Polymethacrylic Acids / Q000737:chemistry; D019279:Resin Cements / Q000737:chemistry; D033081:Shear Strength; D012997:Solvents / Q000737:chemistry; D013314:Stress, Mechanical; D013499:Surface Properties; D013500:Surface Tension; D014867:Water / Q000737:chemistry; D017155:Wettability
chemical_list: C112828:Clearfil AP-X; C515604:Clearfil Tri-S Bond; D003738:Dental Cements; C498353:G-Bond; D008689:Methacrylates; D009281:Naphthalenes; D011109:Polymethacrylic Acids; D019279:Resin Cements; D012997:Solvents; D014867:Water; C020946:triethylene glycol dimethacrylate; C031721:naphthalene; D000431:Ethanol; D011092:Polyethylene Glycols; D017438:Bisphenol A-Glycidyl Methacrylate; C005044:hydroxyethyl methacrylate; D019855:Ethylene Glycol; D010100:Oxygen