title: In vitro microTBS of one-bottle adhesive systems: sound versus artificially-created caries-affected dentin.
abstract: This in vitro study aimed to evaluate a pH-cycling model for simulation of caries-affected dentin (CAD) surfaces, by comparing the bond strength of etch-and-rinse adhesive systems on sound and artificially-created CAD. Dentin substrates with different mineral contents and morphological patterns were created by submitting buccal bovine dentin to the following treatments: (1) immersion in artificial saliva during the experimental period (sound dentin, SD), or (2) induction to a CAD condition by means of a dynamic pH-cycling model (8 cycles, demineralization for 3 h followed by mineralization for 45 h). The bond strength of Excite or Prime and Bond NT adhesive systems was assessed using the microtensile bond strength (microTBS) test. Dentin microhardness was determined by cross-sectional Knoop evaluations. Resin-dentin morphology after the treatments was examined by scanning electron microscopy. SD produced significantly higher microTBS than CAD for both adhesives evaluated, without differences between materials. CAD exhibited lower microhardness than SD. Morphological analysis showed marked distinctions between SD and CAD bonded interfaces. Under the conditions of this study, differences in morphological pattern and dentin mineral content may help to explain resin-dentin bond strengths. The proposed pH-cycling model may be a suitable method to simulate CAD surfaces for bonding evaluations.
authors.affiliation: Department of Restorative Dentistry, Piracicaba School of Dentistry, University of Campinas, São Paulo, Brazil.
authors.forename: Maria Carolina G
authors.initials: MC
authors.lastname: Erhardt
authors.forename: José Augusto
authors.initials: JA
authors.lastname: Rodrigues
authors.forename: Thiago Assunção
authors.initials: TA
authors.lastname: Valentino
authors.forename: André Vicente
authors.initials: AV
authors.lastname: Ritter
authors.forename: Luiz André Freire
authors.initials: LA
authors.lastname: Pimenta
mesh_terms: D000268:Adhesiveness; D000818:Animals; D002417:Cattle; D001840:Dental Bonding / Q000379:methods*; D003731:Dental Caries / Q000473:pathology*; D003804:Dentin / Q000737:chemistry*; D017220:Dentin-Bonding Agents / Q000737:chemistry*; D006244:Hardness; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D007180:Incisor / Q000473:pathology; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D015233:Models, Statistical; D013499:Surface Properties; D013718:Tensile Strength
chemical_list: D017220:Dentin-Bonding Agents