ABSTRACT
Titanium-based alloys are used in orthopedic applications as fixation elements, hard tissue replacements in artificial bones, and dental implants. Despite their wide range of applications, metallic implant defects and failures arise due to inadequate mechanical bonding, postoperative clotting problems, aseptic loosening, and infections. To improve the surface bioactivity and reduce the corrosion rate of the Ti6Al4V alloy, multi-layered coatings (HAp, BG, Cs, and Hep) were applied via electrophoretic deposition (EPD). XRD images showed the presence of HAp within the coating. In vitro investigation: cell line NIH-3T3 fibroblasts were seeded on the non-coated and coated Ti6Al4V substrates, and their cellular behavior was evaluated. The results indicated that the HApBGCsHep coating could enhance the adhesion and proliferation of NIH 3T3 cells. In addition, the potentiodynamic polarization results are compatible with the in vitro outcome.
ABSTRACT
BACKGROUND: For long-term success of dental implants, it is essential to maintain the health of the surrounding soft tissue barrier, which protects the bone-implant interface from the microorganisms. Although implants based on titanium and its alloys still dominate the dental implant market, alumina (Al2 O3 ) and zirconia (ZrO2 ) implant systems are widely used in the area. However, they provide smooth and bioinert surfaces in the transmucosal region, which poorly integrate with the surrounding tissues. OBJECTIVE: The main aim of this research was to investigate the surface characteristics and biocompatibility of chitosan-coated alumina and zirconia surfaces. MATERIALS AND METHODS: The substrates were coated via solution casting technique. Additionally, an aging process with a thermocycle apparatus was applied on the coated materials to mimic the oral environment. To define the morphology and chemical composition of the surfaces of untreated, chitosan-coated, and chitosan-coated-aged samples, scanning electron microscopy and energy dispersive X-ray spectrometry were used. The phases and bonds characterized by Fourier transform infrared spectroscopy and X-ray diffraction analysis. The human gingival fibroblast cells were used to evaluate cytocompatibility by a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium salt assay. RESULTS: It was observed that both substrates were successfully coated with chitosan and the aging process did not significantly affect the integrity of the coating. The attachment and proliferation of human gingival fibroblast cells were shown to be good on both kinds of chitosan-coated surfaces. CONCLUSION: Coating zirconia and alumina surfaces with chitosan is an efficient surface modification for increasing biocompatibility and bioactivity of these materials in vitro.
