Biofilm-associated
diseases are one of the main causes of implant failure. Currently,
the development of implant surface treatment goes beyond the osseointegration
process and focuses on the creation of surfaces with antimicrobial
action and with the possibility to be re-activated (i.e., light source
activation). Titanium dioxide (TiO2), an excellent photocatalyst
used for photocatalytic antibacterial applications, could be a great
alternative, but its efficiency is limited to the ultraviolet (UV)
range of the electromagnetic spectrum. Since UV radiation has carcinogenic
potential, we created a functional TiO2 coating codoped
with nitrogen and bismuth via the plasma electrolytic oxidation (PEO)
of titanium to achieve an antibacterial effect under visible light
with re-activation potential. A complex surface topography was demonstrated
by scanning electron microscopy and three-dimensional confocal laser
scanning microscopy. Additionally, PEO-treated surfaces showed greater
hydrophilicity and albumin adsorption compared to control, untreated
titanium. Bismuth incorporation shifted the band gap of TiO2 to the visible region and facilitated higher degradation of methyl
orange (MO) in the dark, with a greater reduction in the concentration
of MO after visible-light irradiation even after 72 h of aging. These
results were consistent with the in vitro antibacterial effect, where
samples with nitrogen and bismuth in their composition showed the
greatest bacterial reduction after 24 h of dual-species biofilm formation
(Streptococcus sanguinis and Actinomyces naeslundii) in darkness with a superior
effect at 30 min of visible-light irradiation. In addition, such a
coating presents reusable photocatalytic potential and good biocompatibility
by presenting a noncytotoxicity effect on human gingival fibroblast
cells. Therefore, nitrogen and bismuth incorporation into TiO2 via PEO can be considered a promising alternative for dental
implant application with antibacterial properties in darkness, with
a stronger effect after visible-light application.
Polymicrobial infections
are one of the most common reasons for inflammation of surrounding
tissues and failure of implanted biomaterials. Because microorganism
adhesion is the first step for biofilm formation, physical–chemical
modifications of biomaterials have been proposed to reduce the initial
microbial attachment. Thus, the use of superhydrophobic coatings has
emerged because of their anti-biofilm properties. However, these coatings
on the titanium (Ti) surface have been developed mainly by dual-step
surface modification techniques and have not been tested using polymicrobial
biofilms. Therefore, we developed a one-step superhydrophobic coating
on the Ti surface by using a low-pressure plasma technology to create
a biocompatible coating that reduces polymicrobial biofilm adhesion
and formation. The superhydrophobic coating on Ti was created by the
glow discharge plasma using Ar, O2, and hexamethyldisiloxane
gases, and after full physical, chemical, and biological characterizations,
we evaluated its properties regarding oral biofilm inhibition. The
newly developed coating presented an increased surface roughness and,
consequently, superhydrophobicity (contact angle over 150°) and
enhanced corrosion resistance (p < 0.05) of the
Ti surface. Furthermore, proteomic analysis showed a unique pattern
of protein adsorption on the superhydrophobic coating without drastically
changing the biologic processes mediated by proteins. Additionally,
superhydrophobic treatment did not present a cytotoxic effect on fibroblasts
or reduction of proliferation; however, it significantly reduced (≈8-fold
change) polymicrobial adhesion (bacterial and fungal) and biofilm
formation in vitro. Interestingly, superhydrophobic coating shifted
the microbiological profile of biofilms formed in situ in the oral
cavity, reducing by up to ≈7 fold pathogens associated with
the peri-implant disease. Thus, this new superhydrophobic coating
developed by a one-step glow discharge plasma technique is a promising
biocompatible strategy to drastically reduce microbial adhesion and
biofilm formation on Ti-based biomedical implants.
The effect of a photopolymerized glaze on different properties of acrylic resin (AR) for ocular prostheses submitted to accelerated aging was investigated. Forty discs were divided into 4 groups: N1 AR without glaze (G1); colorless AR without glaze (G2); N1 AR with glaze (G3); and colorless AR with glaze (G4). All samples were polished with sandpaper (240, 600 and 800-grit). In G1 and G2, a 1200-grit sandpaper was also used. In G3 and G4, samples were coated with MegaSeal glaze. Property analysis of color stability, microhardness, roughness, and surface energy, and assays of atomic force microscopy, scanning electron microscopy, and energy-dispersive spectroscopy were performed before and after the accelerated aging (1008h). Data were submitted to the ANOVA and Tukey Test (p<0.05). Groups with glaze exhibited statistically higher color change and roughness after aging. The surface microhardness significantly decreased in groups with glaze and increased in groups without glaze. The surface energy increased after the aging, independent of the polishing procedure. All groups showed an increase of surface irregularities. Photopolymerized glaze is an inadequate surface treatment for AR for ocular prostheses and it affected the color stability, roughness, and microhardness. The accelerated aging interfered negatively with the properties of resins.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.