In vitro electrical impedance spectroscopy of human dentine: the effect of restorative materials

BERTA RIVAS; PABLO M. BOTTA; PURIFICACIÓN VARELA; BENJAMÍN MARTÍN; ALFONSO FONDADO; JOSÉ RIVAS

BIOELECTROMAGNETICS.

WILEY-LISS, DIV JOHN WILEY & SONS INC

Año: 2008 vol. 29 p. 163 - 168

0197-8462

The influence of different restorative materials on in vitro dielectric properties of sound dentine was investigated. The tested samples consisted in three-layer materials composed by 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 hours. Also, sections of sound dentine were similarly prepared for electrical tests. Complex dielectric permittivity of these specimens was determined in a wide frequency range using the parallel-plate capacitor technique. Very similar dielectric responses of neat dentine and amalgam-dentine material were observed. This is explained on the basis on 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 a careful handling of electrical data should be made when they were used in caries diagnosis on restored teeth.