Pure titanium (Ti) and its alloys are the gold standard for dental implants because a stable titanium dioxide passive film provides excellent corrosion resistance in physiological environments. In this study, we aimed to examine electrochemical interactions between Ti and cobalt–chromium–molybdenum alloy (CoCrMo), and between a novel Ti–magnesium composite (BIACOM TiMg) and CoCrMo, when immersed in everyday solutions representing beverage or oral hygiene exposure. Test solutions included Coca-Cola^®, lemon juice, Elmex^® fluoride gel, Listerine^® Cool Mint, and Sensodyne^® fluoride paste. Immersion experiments paired Ti sticks with CoCrMo sticks and, separately, BIACOM TiMg with CoCrMo sticks, with three measurements per configuration. When galvanically coupled with CoCrMo, immersion in Coca-Cola produced galvanic potential differences of ~983 mV for the BIACOM TiMg-CoCrMo couple and 830 mV for the commercially pure grade 4 (CP4) Ti-CoCrMo couple, indicating significant electrochemical instability. Both materials showed significant potential increases in Elmex fluoride gel. Listerine Cool Mint and Sensodyne fluoride exposure produced electrochemical interactions exceeding 200 mV. Significant differences in corrosion stability were observed between CP4 Ti and BIACOM TiMg. These findings indicate that material pairing and electrolyte environment significantly influence galvanic behavior, with the Ti-Mg composite showing greater susceptibility than CP4 Ti, informing dental/biomedical material selection in oral environments.

Implantable intrabody communication (IBC) is a method that enables low-power, high-security communication between implanted in-body devices that could track biomedical signals and an on-body receiver by using the human body as a communication medium. As the human body consists of various tissues that each have different conductivity, this paper explores the effects of the conductivity of the communication medium on the channel gain over a wide frequency range from 10 MHz up to 300 MHz through the measurements and two models: an electrical circuit model and a FEM simulation model. Measurements are conducted using a liquid phantom with varying conductivity values from 0 S/m up to 1 S/m, covering most human tissues in the frequency range of interest. The circuit and FEM models are designed to mimic the measurement setup in order to verify the measurement results. Results show that the circuit model predicts the communication channel characteristics well at lower frequencies but cannot account for the influence of the measurement setup at higher frequencies. The influence of wire inductances, which can cause a resonant behavior when measuring at frequencies above 100 MHz, was observed using the FEM model. The results also show that the higher the conductivity of the tissue in which the device is implanted, the lower the gain of the signal, with the difference in gain being more prominent when capacitive termination with a high-impedance load is used instead of low-impedance termination. These findings provide valuable insight for selecting the appropriate interface (low-impedance vs. high-impedance termination) across specific frequency ranges for in-body to on-body (IB2OB) communication devices, while illustrating the effect of tissue conductivity on an IBC channel, thereby supporting the optimized design and implementation of reliable IB2OB communication systems.

Pure titanium (Ti) and its alloys are the "gold standard" for dental implants due to their stable titanium dioxide passive film providing excellent corrosion resistance in physiological environments. This study examined electrochemical interactions between Ti and cobalt-chromium-molybdenum alloy (CoCrMo), and between a novel Ti-Magnesium composite (BIACOM TiMg) and CoCrMo, when immersed in everyday solutions representing beverage or oral hygiene exposure. Test solutions included Coca-Cola®, lemon juice, Elmex® fluoride gel, Listerine® Cool Mint, and Sensodyne® fluoride paste. The immersion experiment paired Ti sticks with CoCrMo sticks, then BIACOM TiMg composite with CoCrMo sticks, with three measurements per configuration. Coca-Cola immersion increased electrochemical potential to ~983 mV for BIACOM TiMg and ~830 mV for CP4 titanium. Significant potential increases occurred in Elmex fluoride gel for both materials. Listerine Cool Mint and Sensodyne Fluoride exposures showed electrochemical interactions exceeding 200 mV. Marked differences in corrosion stability between CP4 titanium and BIACOM TiMg composite were confirmed. Findings indicate that material pairing and electrolyte environment significantly influence galvanic and corrosion behavior, with Ti-Mg composite showing higher susceptibility than CP4 titanium under tested conditions, impacting dental/biomedical material selection in oral environments.