title: In vitro electrical impedance spectroscopy of human dentine: the effect of restorative materials.
abstract: The influence of different restorative materials on in vitro dielectric properties of sound dentine was investigated. The studied samples were three-layer materials consisting of successive disks of dentine and silver amalgam or nanohybrid composite resin. Before being tested, the samples were maintained in physiological solution never more than 48 h from the extraction. Also, sections of intact dentine were similarly prepared for electrical measurements. Complex dielectric permittivity of these specimens was determined in a wide frequency range using the parallel-plate capacitor technique. Very similar dielectric responses of intact dentine and amalgam-dentine material were observed. This is explained on the basis of high dc conductivity exhibited by both samples. In contrast, resin-dentine specimen revealed a much more insulating behavior. A simple theoretical model for heterogeneous systems could be applied to these dental three-layer materials. The dielectric properties of restored dentine are strongly dependent on the kind of restorative material employed in each case. This suggests that electrical data should be used carefully in caries diagnosis on restored teeth.
authors.affiliation: Departamento de Estomatología, Universidad de Santiago de Compostela, Campus Universitario Sur, Santiago de Compostela, Spain.
authors.forename: Berta
authors.initials: B
authors.lastname: Rivas
authors.forename: Pablo M
authors.initials: PM
authors.lastname: Botta
authors.forename: Purificación
authors.initials: P
authors.lastname: Varela
authors.forename: Benjamín
authors.initials: B
authors.lastname: Martín
authors.forename: Alfonso
authors.initials: A
authors.lastname: Fondado
authors.forename: Jose
authors.initials: J
authors.lastname: Rivas
mesh_terms: D001641:Bicuspid / Q000737:chemistry*; D003764:Dental Materials / Q000737:chemistry*; D003793:Dental Restoration, Permanent; D003804:Dentin / Q000737:chemistry*; D006801:Humans; D066298:In Vitro Techniques; D010992:Plethysmography, Impedance / Q000379:methods*; D013057:Spectrum Analysis / Q000379:methods*
chemical_list: D003764:Dental Materials