Graphene-based Antibacterial Coatings for Dental Applications

Over the past few years, orthodontic treatments are influenced by aesthetic considerations, methods for the treatment of malocclusions or dental misalignment defects, alternatives to the classic metal fixed devices. A recent survey has shown that while traditional metal brackets are aesthetically accepted only by 55% of adults, clear aligners are accepted by more than 90%, instead. However, it seems rational that the mechanical properties should be coupled with antibacterial material to reduce the risk of developing caries and periodontal problems. For this reason, graphene-based materials are emerging as promising antimicrobial agents. In particular, Graphene Nanoplatelets (GNPs) are cheap, easy to produce, have excellent mechanical and antibacterial properties. And also, the only mechanism observed with GNPs was the punctuation of cellular membrane with their sharp edges (nano knife effect), without any production of reactive oxygen species (ROS). Conroy et al. have shown that non-oxidized nanoplatelets typically do not produce ROS, demonstrating their high biosafety, thus enabling their use as antimicrobial agents. Therefore, this work presents an innovative solution for developing graphene-based antibacterial coatings through a simple spray deposition method on dental surfaces to reduce pathogen growth and infections during orthodontic treatment. The surface morphology of treated and untreated dental surfaces is characterized through a Field Emission Scanning Electron Microscopy (FE-SEM) at Sapienza Nanotechnology and Nanoscience laboratory (SNN-Lab). From FE-SEM images, it is evident that GNPs were well coated and uniformly dispersed on dental surfaces. The ability of bacterial survival on the dental surface was evaluated by the Colony Count Method (Colony Forming Units, CFU). The cell viability test against Staphylococcus aureus and pseudomonas aeruginosa bacteria reveals that GNPs treated dental surfaces show a significantly high reduction of ÏU with time. Thus, the produced graphene-based antibacterial coatings were suitable for dental applications.