title: Resistance to degradation of resin-dentin bonds produced by one-step self-etch adhesives.
abstract: The objective of this article is to evaluate the resistance to degradation of resin-dentin bonds formed with three one-step adhesives. Flat, mid-coronal dentin surfaces were bonded with the self-etching adhesives [Tokuyama Bond Force (TBF), One Up Bond F Plus (OUB), and G-Bond (GB)]. The bonded teeth were subjected to fatigue loading, chemical degradation, and stored in distilled water for four time periods (up to 12 months). Specimens were tested for microtensile bond strength and microleakage. Fractographic analysis was performed by scanning electron microscopy. Bonded interfaces were examined by light microscopy using Masson's trichrome staining. An atomic force microscope was employed to analyze phase separation and surface nanoroughness (Ra) at the polymers. Vickers microhardness and the degree of the conversion (DC) were also determined. ANOVA and multiple comparisons tests were performed. Bond strength significantly decreased after the chemical challenge, but not after load cycling. Aging decreased bond strength after 6 months in TBF and GB, in OUB after 12 months. An increase of the nonresin protected collagen zone occurred in all groups, after storing. TBF showed the highest roughness, microhardness, and DC values, and GB showed the lowest. Mild self-etch one-step adhesives (TBF/OUB) showed a higher degree of cure, lower hydrophilicity, and major resistance to degradation of resin-dentin bonds when compared to highly acidic self-etching adhesive (GB).
authors.affiliation: University of Granada, Faculty of Dentistry, Dental Materials Section, Colegio Máximo de Cartuja s/n, 18071, Granada, Spain. toledano@ugr.es
authors.forename: Manuel
authors.initials: M
authors.lastname: Toledano
authors.forename: Inmaculada
authors.initials: I
authors.lastname: Cabello
authors.forename: Monica
authors.initials: M
authors.lastname: Yamauti
authors.forename: Marcelo
authors.initials: M
authors.lastname: Giannini
authors.forename: Fátima S
authors.initials: FS
authors.lastname: Aguilera
authors.forename: Estrella
authors.initials: E
authors.lastname: Osorio
authors.forename: Raquel
authors.initials: R
authors.lastname: Osorio
mesh_terms: D000134:Acid Etching, Dental / Q000379:methods*; D000704:Analysis of Variance; D019412:Anatomy, Cross-Sectional; D003094:Collagen / Q000737:chemistry; D001840:Dental Bonding; D003738:Dental Cements / Q000737:chemistry*; D003799:Dental Stress Analysis; D006244:Hardness; D006245:Hardness Tests / Q000379:methods; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D018625:Microscopy, Atomic Force; D008855:Microscopy, Electron, Scanning; D008964:Molar, Third / Q000737:chemistry; D036103:Nanotechnology / Q000379:methods; D012117:Resins, Synthetic / Q000737:chemistry*; D013499:Surface Properties; D013718:Tensile Strength; D013997:Time Factors; D014867:Water / Q000737:chemistry
chemical_list: D003738:Dental Cements; D012117:Resins, Synthetic; D014867:Water; D003094:Collagen