Accurate Empirical Fractional-Order Electrical Models of Young and Old Dentines.

Electrical impedance spectroscopy (EIS) is a fast, non-invasive, and safe technique for bioimpedance measurement. In dental research, EIS has been used to detect tooth cracks and caries with higher accuracy than visual and radiographic methods. Recently, a study has been reported on effect of age on impedance measurements for two age groups by employing EIS. The aim of that study was to demonstrate the usefulness of fractional calculus in equivalent circuit modeling. In proposed double dispersion Cole impedance (C-C) models, both resistance and pseudo-capacitance values were found to be significantly different for both age groups. However, in our study, the first time it was found out that proposed models' total pseudo-capacitance values of both young and old dentines can be reduced by 34% and 7.5%, respectively, if recurrent electrical impedance model for n = 2 bifurcations to be used. Secondly, new empirical fractional-order electrical models of human tooth using the optimized Valsa network with EIA standard compliant RC values are reported that provide better understanding of the structure of dentine from resistance and capacitance point of view.