title: Bond strength and bioactivity of Zn-doped dental adhesives promoted by load cycling.
abstract: The purpose of this study was to evaluate if mechanical loading influences bioactivity and bond strength at the resin-dentin interface after bonding with Zn-doped etch-and-rinse adhesives. Dentin surfaces were subjected to demineralization by 37% phosphoric acid (PA) or 0.5 M ethylenediaminetetraacetic acid (EDTA). Single bond (SB) adhesive—3M ESPE—SB+ZnO particles 20 wt% and SB+ZnCl2 2 wt% were applied on treated dentin to create the groups PA+SB, SB+ZnO, SB+ZnCl2, EDTA+SB, EDTA+ZnO, and EDTA+ZnCl2. Bonded interfaces were stored in simulated body fluid for 24 h and tested or submitted to mechanical loading. Microtensile bond strength (MTBS) was assessed. Debonded dentin surfaces were studied by high-resolution scanning electron microscopy. Remineralization of the bonded interfaces was assessed by atomic force microscope imaging/nanoindentation, Raman spectroscopy/cluster analysis, and Masson's trichrome staining. Load cycling (LC) produced reduction in MTBS in all PA+SB, and no change was encountered in EDTA+SB specimens, regardless of zinc doping. LC increased the mineralization and crystallographic maturity at the interface; a higher effect was noticed when using ZnO. Trichrome staining reflected a narrow demineralized dentin matrix after loading of dentin surfaces that were treated with SB-doped adhesives. This correlates with an increase in mineral platforms or plate-like multilayered crystals in PA or EDTA-treated dentin surfaces, respectively.
authors.affiliation: Faculty of Dentistry,Dental Materials Section,University of Granada,Colegio Máximo de Cartuja s/n,18071 Granada,Spain.
authors.forename: Manuel
authors.initials: M
authors.lastname: Toledano
authors.affiliation: Faculty of Dentistry,Dental Materials Section,University of Granada,Colegio Máximo de Cartuja s/n,18071 Granada,Spain.
authors.forename: Fátima S
authors.initials: FS
authors.lastname: Aguilera
authors.affiliation: Faculty of Dentistry,Dental Materials Section,University of Granada,Colegio Máximo de Cartuja s/n,18071 Granada,Spain.
authors.forename: Estrella
authors.initials: E
authors.lastname: Osorio
authors.affiliation: Faculty of Dentistry,Dental Materials Section,University of Granada,Colegio Máximo de Cartuja s/n,18071 Granada,Spain.
authors.forename: Inmaculada
authors.initials: I
authors.lastname: Cabello
authors.affiliation: Faculty of Dentistry,Dental Materials Section,University of Granada,Colegio Máximo de Cartuja s/n,18071 Granada,Spain.
authors.forename: Manuel
authors.initials: M
authors.lastname: Toledano-Osorio
authors.affiliation: Faculty of Dentistry,Dental Materials Section,University of Granada,Colegio Máximo de Cartuja s/n,18071 Granada,Spain.
authors.forename: Raquel
authors.initials: R
authors.lastname: Osorio
mesh_terms: D000328:Adult; D001840:Dental Bonding / Q000295:instrumentation; D003738:Dental Cements / Q000737:chemistry*; D003804:Dentin / Q000737:chemistry; D017220:Dentin-Bonding Agents / Q000737:chemistry; D005260:Female; D006801:Humans; D008297:Male; D013718:Tensile Strength; D055815:Young Adult; D015032:Zinc / Q000737:chemistry*
chemical_list: D003738:Dental Cements; D017220:Dentin-Bonding Agents; D015032:Zinc
keywords: bond strength