A bi-layered coating of nanofluroapatite/nanochitosan to improve antimicrobial and biological properties of zirconia-based dental implant.

INTRODUCTION: Yttria-stabilized zirconia has mechanical properties akin to titanium dental implants but does not integrate with osseous tissues. A bi-layered nano-fluorapatite/nano-chitosan (nFA/nCS) coating was synthesized to improve osseointegration potential and antimicrobial properties of zirconia. MATERIALS AND METHODS: Zirconia discs were coated with bi-layered nFA/nCS using sol-gel route. The integrity of the coating was tested by X-ray, atomic force microscopy, and field emission scanning electron microscopy-energy dispersive spectroscopy. The adhesion of coating to zirconia was calculated by adhesive tape test and ultrasonic vibration. By measuring the optical contact angle, the coated and non-coated samples' differences in wettability were assessed. Anti-microbial activity was investigated against S. aureus and E. coli and cytotoxicity examined using osteoblast-like cells. Results: The bi-layered nFA/nCS coating was 9.26 μm thick and exhibited acceptable adhesion strength (0.50 ±1.1 N/mm) to zirconia and greater resistance to ultrasonic-induced delamination than the single nFA coating and the water contact angle decreased to 5°, and surface roughness increased to 121.3 nm. The coating decreased the count of both bacterial strains and was not cytotoxic to mammalian cells. Conclusion: nFA/nCS coating exhibited acceptable adhesion and enhanced bioactivity and antimicrobial activity rendering it a potential material for replacing titanium dental implants. Functionalizing zirconia with nFA/nCS is a cost-effective alternative to titanium implants making them more available to the general public.&#xD.