Numerical Modelling of Bioimpedance Measurement in Dentistry

Introduction. In dentistry, oral inflammations are very frequent 1 and can have serious consequences (e.g. peri-implantitis is the main cause of implant failure 2). Human tissues impedance values vary with their physiological/pathological state 3, so it could be used with diagnostic aims. Objectives. The authors numerically analyze the bioimpedance measurement by means of 3D Finite Element Method (FEM) of three teeth models, to verify the possibility of distinguishing between healthy and inflamed tissues. Methods. Various numerical models were considered, both of healthy tooth roots (i.e. canine, incisor and premolar) and of dental implants (i.e. premolar dental implant). Geometric and electrical properties were taken from the literature 4,5, paying particular attention to the inflamed tissue 3. In order to carry out a parametric study, different-sized inflamed tissue volumes were considered, besides different electrodes shapes and dimensions as well as positioning. Results. Healthy and inflamed tissues impedances were compared and differences of 6÷20% have been found, depending on the considered parameters (e.g. inflammation volume and severity). Conclusions. Results show that the change due to the inflammatory process is sufficiently pronounced to discriminate between healthy and inflamed tissues, so bioimpedance measurements can be used to locate inflammation; moreover, results from parametric study can aid in the design of a proper bioimpedance meter. In conclusion, bioimpedancemetry appears to be useful in the diagnostics of inflamed tissues in dentistry.