title: Multiscale characterization of partially demineralized superficial and deep dentin surfaces.
abstract: The objective of this study was to address the following question: 'Which properties are modified in partially demineralized surfaces, compared with non-demineralized dentin surfaces, following orthophosphoric acid-etching as performed in clinical procedures?'. For this purpose, the complementary techniques atomic force microscopy/spectroscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and contact angle measurements were used to provide a multiscale characterization of the dentin substrate undergoing the acidic preconditioning designed to enhance wetting. Special attention was given to the influence of the etching pretreatment on the nanomechanical properties at different levels of dentin surfaces, in both dry and hydrated conditions. The four-sided pyramid model (extended Hertz contact model) proved to be accurate for calculating the apparent Young's modulus, offering new information on the elasticity of dentin. The modulus value notably decreased following etching and surface hydration. This study underlines that after the acid etching pretreatment the contribution of the nanomechanical, morphological, and physicochemical modifications has a strong influence on the dentin adhesion properties and thus plays a significant role in the coupling of the adhesive-resin composite build-up material at the dentin surface.
authors.affiliation: Laboratory of Natural Polymers, Bioactive and Biocompatible Materials, Petru Poni Institute of Macromolecular Chemistry of Romanian Academy, Iasi, Romania. impelin@icmpp.ro
authors.forename: Irina M
authors.initials: IM
authors.lastname: Pelin
authors.forename: Ana-Maria
authors.initials: AM
authors.lastname: Trunfio-Sfarghiu
authors.forename: Pierre
authors.initials: P
authors.lastname: Farge
authors.forename: Agnes
authors.initials: A
authors.lastname: Piednoir
authors.forename: Christophe
authors.initials: C
authors.lastname: Pirat
authors.forename: Stella M M
authors.initials: SM
authors.lastname: Ramos
mesh_terms: D000134:Acid Etching, Dental; D003804:Dentin / Q000737:chemistry*; D055119:Elastic Modulus; D006801:Humans; D018625:Microscopy, Atomic Force; D008855:Microscopy, Electron, Scanning; D008964:Molar, Third; D010756:Phosphoric Acids / Q000009:adverse effects*; D013052:Spectrometry, X-Ray Emission; D013499:Surface Properties; D017001:Tooth Demineralization / Q000139:chemically induced*
chemical_list: D010756:Phosphoric Acids
keywords: apparent elastic modulus; deep dentin; mineral/organic ratio; superficial dentin; surface morphology