Background: Although tantalum (Ta)-based coatings have been proven to have good antibacterial activity, the underlying mechanism and in vivo biological performance remain unclear, which are essential for the clinical application of Ta-coated biomaterials as dental implants.
Purpose: The main objective of this study is to investigate the antibacterial activity of Ta-modified titanium (Ti) implants against peri-implantitis-related microbes and the potential molecular mechanisms.
Methods: Fusobacterium nucleatum  and Porphyromonas gingivalis  were selected to evaluate the antibacterial activity and potential antibacterial mechanism of Ta modification. The in vivo biocompatibility of Ta-modified implants was also evaluated.
Results: The results showed that Ta-modified surface performed excellent antimicrobial activity against Fusobacterium nucleatum  and Porphyromonas gingivalis . Micro galvanic might be formed between the incorporated Ta and the Ti base, which could consume the protons and result in decreased ATP synthesis and increased ROS generation. The gene expression of bacterial virulence factors associated with cellular attachment, invasion and viability as the target of ROS was downregulated. Importantly, in vivo biological studies showed that Ta modification significantly promoted the osseointegration of implants by stimulating the expression of bone-forming proteins.
Conclusion: This study may provide some insights into clinical applications of Ta-coated Ti implants, especially in possibly infected situations.
Keywords: tantalum-coating, antibacterial activity, ATP synthesis, ROS generation, osseointegration