Antibacterial potential of silver and zinc loaded plasma-electrolytic oxidation coatings for dental titanium implants

Peri-implantitis is known as an inflammatory condition affecting the soft and hard tissue around dental implants. A promising strategy to prevent these conditions is the use of antibacterial implants. This study aimed to evaluate the antibacterial potential of titanium (Ti) dental implants modified using plasma-electrolytic oxidation (PEO). The modified surfaces were subsequently loaded with silver (Ag) (n = 6) and zinc (Zn) (n = 6) ions and compared to unloaded Ti specimens (n = 6), with untreated specimens serving as controls. The specimens (each n = 5) were incubated in a culture medium containing a mixture of specific anaerobic bacterial strains. Scanning electron microscopy (SEM) was used to visualize the bacterial biofilm on each specimen. In addition, total bacterial deoxxyribonucleic acid (DNA) and the number of viable bacteria were determined using quantitative real-time polymerase chain reaction (qrt-PCR) and colony forming unit analysis (CFU), respectively. The results of the CFU analysis showed a 2 log (99%) reduction in viable bacteria in the samples loaded with Ag and Zn compared to the unloaded control group (p < 0.05). Moreover, significantly lower bacterial DNA counts were detected with a 5 log reduction (99.999%) in the Ag and Zn samples compared to the positive control group (bacterial mixed culture solution, p < 0.05). Therefore, it was considered that Ag and Zn loaded Ti implants may be a promising addition to current approaches to enable advanced antibacterial dental implants. However, further studies should be conducted to evaluate the in vivo cytocompatibility of the developed specimens.