Low-Cost Deposition of Antibacterial Ion-Substituted Hydroxyapatite Coatings onto 316L Stainless Steel for Biomedical and Dental Applications

Abstract

Substitutions of ions into an apatitic lattice may result in antibacterial properties. In this study, magnesium (Mg)-, zinc (Zn)-, and silicon (Si)-substituted hydroxyapatite (HA) were synthesized using a microwave irradiation technique. Polyvinyl alcohol (PVA) was added during the synthesis of the substituted HA as a binding agent. The synthesized Mg-, Zn-, and Si-substituted HAs were then coated onto a 316L-grade stainless-steel substrate using low-cost electrophoretic deposition (EPD), thereby avoiding exposure to high temperatures. The deposited layer thickness was measured and the structural, phase and morphological analysis were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and scanning electron microscope (SEM), respectively. The bacterial adhesion of Staphylococcus aureus was characterized at 30 min, 2 h and 6 h. The results showed homogeneous, uniform thickness (50–70 µm) of the substrate. FTIR and XRD showed the characteristic spectral peaks of HA, where the presence of Mg, Zn and Si changed the spectral peak intensities. The Mg–HA coating showed the least bacterial adhesion at 30 min and 2 h. In contrast, the Si–HA coating showed the least adhesion at 6 h. EPD showed an effective way to get a uniform coating on bio-grade metal implants, where ionic-substituted HA appeared as alternative coating material compared to conventional HA and showed the least bacterial adhesion.

The trends of dental biomaterials research and future directions: A mapping review

“…Plenty of research is being carried out on developing novel techniques of surface modifications of dental implants which aim at quick and durable osseointegration. Some of the novel methods of surface modifications included antibiotic and nano-silver loaded bone cements, and selective laser melted titanium tantalum niobium zirconium (Ti-Ta-Nb-Zr) alloy ( Dziaduszewska et al, 2019 ), chemical vapor deposition of titanium nitride on cobalt chromium alloys ( Song et al, 2020 ), electrophorectic deposition of ionic-substituted hydroxyapatites ( Khan and Awais, 2020 ), and microwave brazing using gold nano-dots ( Tamang et al, 2019 ).…”

Microwave-assisted synthesis of composites based on titanium and hydroxyapatite for dental implantation

“…[43][44][45] For instance, Ag + is the most commonly used dopant ion because of its antibacterial role. [46][47][48] The study of the substitution behavior of HA in silver nitrate solution demonstrated that microwave could disturb the solvent layer around the ions through its non-thermal effect and significantly change the lattice parameters of HA, thus promoting the diffusion of Ag + to the interior. 17,47 With alkalitreated Ti6Al4V as the substrate, pure HA coatings were prepared under microwave irradiation at 1400 W for 4 min using a solution with a Ca/P molar ratio of 1.67 (0.14 mol L −1 Ca 2+ ).…”

“…However, there were potential risks of non-uniform coating thickness and unstable composition after treatment, which led to substrate exposure. 46,54 It was caused by the insufficient concentration of Ca 2+ and PO 4 3− generated by the degradation of amorphous Ca-P in the solution alone. Further adjustments are required for optimizing the solution composition for the treatment (Table 2).…”

Calcium Phosphate Loaded Biopolymer Composites—A Comprehensive Review on the Most Recent Progress and Promising Trends

“…The preparations, thorough characterizations, and properties of these materials have been exhaustively studied and reported in numerous papers and summarized in reviews [34][35][36][37][38][39][40]. A further purpose of ionic substitution is to achieve antibacterial properties, using silver or other specific additives [41,42]. Furthermore, there is an emerging effort to prepare CaP particles from natural sources, such as fishbone [43,44], oyster shell [45], eggshell [46,47], mussel shell [48], snail shell [49], as well as bovine origins, and marble [50].…”