Investigation of Surface Structure and Biocompatibility of Chitosan-Coated Zirconia and Alumina Dental Abutments

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 (Al2O3) 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.