Biocompatibility Evaluation of Surface-Modified Orthodontic Wires Using Graphene Layer

The biocompatibility of orthodontic archwires is crucial for ensuring patient safety and the long-term success of orthodontic treatment. This study evaluated the biocompatibility of stainless steel (SS) and nickel-titanium (Ni-Ti) orthodontic archwires, as well as stainless steel metal brackets, before and after the application of a graphene coating. The assessment was based on the materials' effects on a fibroblast cell line and on the development of a foetal chicken egg embryo. Fibroblasts that had been in temporary contact with steel and NiTi archwires after CW-CVD (cold wall chemical vapour deposition) treatment exhibited changes in morphology in the presence of the material. The materials exhibited moderate cytotoxicity. For metal brackets, the treated samples caused stronger cytotoxic changes in the culture. Unlike graphene-coated implants, where cells were found to directly adhere to the surface, the embryonic tissues did not treat the non-graphene-coated implants as an adhesive material. This study suggests that depositing carbon-based coatings, including graphene, on stainless steel archwires may reduce the cytotoxicity of orthodontic components. Using graphene increases adhesion of the implant surface to membrane-derived cells and the embryonic yolk and does not inhibit the further development of the chicken egg embryo.