Antimicrobial graphene-TiO2 surface coating method for dental implants and abutments

Abstract

Abstract Background Despite the pivotal role of dental implants in restorative dentistry, persistent microbial adhesion and biofilm formation on implant surfaces pose significant challenges, often leading to peri-implant diseases and implant failure. Antimicrobial coatings, particularly those employing titanium dioxide (TiO2) and graphene, show promise in addressing these issues by harnessing their potent antimicrobial properties upon UV activation. Here, we present a facile method for depositing graphene onto TiO2-coated titanium substrates using a bulk turbostratic blasting technique and examine the potential synergistic antibacterial effect of graphene and TiO2 under UV-A irradiation. Methods Titanium and TiO2 substrates were coated with graphene using a bulk turbostratic technique and graphite powder. Deposition of graphene, TiO2, and graphene/TiO2 onto titanium substrates was assessed by Raman microscopy. Antibacterial activity was evaluated by colony-forming unit counts of Escherichia coli suspensions following exposure to varied durations of UV-A light in the presence of TiO2 and graphene/TiO2 substrates. To ensure reproducibility, three samples of each material underwent testing on three distinct days. Statistical comparison among study groups was conducted utilizing a two-tailed Student t-test, where values with P < 0.05 were considered statistically significant. Results Graphene deposition onto TiO2 was successfully accomplished using optimized turbostratic blasting parameters: 3 passes at 6.5 MPa pressure with substrates positioned 5 cm from the nozzle. Verification of successful deposition was confirmed by the presence of D, G, and 2D bands observed in the Raman spectra post-deposition. Importantly, few-layer graphene and not graphite was deposited under these conditions as evidenced by the position and width of the 2D band. Titanium substrates coated solely with TiO2 exhibited near-complete bacterial eradication upon 10 minutes of UV-A exposure. However, the introduction of a graphene layer led to a noticeable reduction in the antibacterial efficacy. Conclusions These results showcase the efficacy of a cost-effective turbostratic blasting method for graphene deposition onto TiO2 surfaces. While the impact of graphene on antimicrobial activity is evident, additional refinement of the TiO2/graphene interface is necessary to harness their synergistic effects. This optimization is pivotal for developing surface coatings that are amenable to processing by dental professionals and can robustly deter bacterial colonization on dental implants and abutments.