title: Adhesiveness of dental resin-based restorative materials investigated with atomic force microscopy.
abstract: This study aimed to show that the polymerization contraction of dental methacrylate-based materials, when used as adhesives on hard substrate, produces voids at the material-substrate interface. This phenomenology is closely related with the nanoleakage and the sealing ability of these materials. One prime/bond system, three restorative composite resins, and one orthodontic bonding system were cured by using mirror-like glass slides as a compliance-free reference substrate. The adhesive surface was analyzed by atomic force microscopy, and the polymerization contraction of bulk material was tested by laser beam-scanning method. Nanoperiodic structure of three-dimensional (3D) images, section analysis, and roughness characteristics (R(a) and R(z)) indicated that polymerization contraction produced voids at the interface. When the adhesive surface was exposed to oral simulating fluids (water, ethanol, and lactic acid solutions), hydrolytic degradation involved some hundreds of nanometers in depth. In visible light-cured (VLC) materials, the interface porosity decreased when an irradiation pause ( approximately 2 min) was carried out during gelation.
authors.affiliation: Department of Public Health, Section of Physics, Istituto Nazionale Fisica della Materia, University of Parma, via Volturno 39, 43100 Parma, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Fano
authors.forename: V
authors.initials: V
authors.lastname: Fano
authors.forename: W Y
authors.initials: WY
authors.lastname: Ma
authors.forename: X G
authors.initials: XG
authors.lastname: Wang
authors.forename: F
authors.initials: F
authors.lastname: Zhu
mesh_terms: D000268:Adhesiveness; D000269:Adhesives; D001672:Biocompatible Materials / Q000737:chemistry*; D001840:Dental Bonding / Q000379:methods*; D003764:Dental Materials / Q000737:chemistry*; D017220:Dentin-Bonding Agents / Q000737:chemistry; D000431:Ethanol / Q000737:chemistry; D006868:Hydrolysis; D021621:Imaging, Three-Dimensional; D019344:Lactic Acid / Q000737:chemistry; D007834:Lasers; D008027:Light; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry*; D018625:Microscopy, Atomic Force / Q000379:methods*; D009970:Orthodontics / Q000379:methods*; D011108:Polymers / Q000737:chemistry; D019279:Resin Cements / Q000737:chemistry; D013499:Surface Properties; D013997:Time Factors; D014867:Water / Q000737:chemistry
chemical_list: D000269:Adhesives; D001672:Biocompatible Materials; D003764:Dental Materials; D017220:Dentin-Bonding Agents; D008689:Methacrylates; D011108:Polymers; D019279:Resin Cements; D014867:Water; D019344:Lactic Acid; D000431:Ethanol