Thermal, Structural, Morphological and Electrical Characterization of Cerium-Containing 45S5 for Metal Implant Coatings

Biomaterial coatings on dental implants are increasingly being used as a solution to the problems of rejection and implant loss. Bioglass® has been seen as a promising material for coating metal implants, increasing the integration rate and improving the bond between the bone and the implant. Multifunctional bioactive glasses can exhibit antibacterial, antitumor and antioxidant effects with the addition of therapeutic ions. The cerium ion has shown an antioxidant effect through mimicking mechanisms and by acting as a scavenger of reactive oxygen species (ROS), which is important for avoiding oxidative stress post-surgery. Furthermore, it is possible to store electrical charge on the bioglass surface, which potentiates osseointegration. In this work, glasses with various percentages of cerium oxide (0.25, 0.5, 1 and 2 mol%) were developed and structurally and electrically analyzed. It was verified that the cerium insertion did not modify the amorphous phase characteristic of the glass but showed an increase in the number of non-bridging oxygens (NBOs). This increase in NBOs did not modify the electrical conductivity in either the ac or dc regime. The similar permittivity values of the glasses also suggest that their storage ability is unchanged with the addition of CeO2. Concerning the impedance spectroscopy (IS) data, a decrease in resistance is visible with the addition of cerium oxide, suggesting a favorable behavior for applications as an antioxidant through the electro-Fenton reaction.