Anti-bacterial performance of Zirconia coatings on Titanium implants

Abstract Bacterial adhesion and colonization are considered to play key roles in the pathogenesis of peri-implant disease, which is an inflammatory process leading the destruction of both soft and hard tissue around a Titanium (Ti) implant. The osseointegration of Ti implants is influenced by their composition and surface treatment. Zirconia (ZrO 2 ) coatings have been shown to improve implant osseointegration in various biomedical fields, including orthopedic devices and dental implants. This study used a twin-gun magnetron sputtering system to deposit ZrO 2 –Sliver (Ag) and ZrO 2 –Copper (Cu) coatings on biograde pure-Ti implant materials. The effects of Ag and Cu on the antibacterial properties of the coated Ti samples were investigated using Staphylococcus aureus ( S . aureus ) and Actinobacillus actinomycetemcomitans ( A . actinomycetemcomitans ), which are found frequently in implant-associated infections. The in vitro antibacterial analyses employed a fluorescence staining method using SYTO9 and bacterial-viability tests on agar plates. Incorporating Ag and Cu into ZrO 2 changed the structure of crystalline ZrO 2 , and the nanostructures of the resulting ZrO 2 –Ag and ZrO 2 –Cu coatings were found to be correlated with the antibacterial performance. The adherence of S . aureus and A . actinomycetemcomitans was less for ZrO 2 samples with a small doping of Cu than for uncoated Ti. The ZrO 2 –Ag coating with an Ag content of 10.6 at.%, which showed hydrophobicity, exhibited the lowest bacterial retention and viability of S . aureus and A . actinomycetemcomitans . The results suggest that ZrO 2 –Ag and ZrO 2 –Cu coatings improve the antibacterial performance relative to pure-Ti implant materials.