Osteogenic nanostructured titanium surfaces with antibacterial properties under conditions that mimic the dynamic situation in the oral cavity

Abstract

The study aim was to assess the impact of different surface nanofeatures on otherwise smooth titanium surfaces on bacterial adhesion as well as on their osteogenic potential. Bacterial adhesion was assessed in the presence of saliva under static and dynamic conditions to approximate both sub- and supragingival conditions in the oral cavity as the gingival seal will be affected by implantation. The ultimate goal was to develop a surface that will reduce biofilm formation but still support osseointegration in vivo. To this end nanotubular or nanopitted surfaces were created on electropolished titanium via electrochemical anodization procedures. Sandblasted/acid etched surfaces (SBAE) were used as a microrough reference. Bacterial adhesion was studied using saliva-precoated samples with S. sanguinis as a typical early colonizer of the oral cavity; osteogenic differentiation was assessed with human bone marrow stromal cells. While bacterial adhesion was reduced on all microsmooth surfaces to an average of 17% surface coverage compared to 61% on SBAE under static conditions, under dynamic conditions the nanopitted surface had a significant impact on bacterial adhesion. Here fluid flow removed all bacteria. By comparison, the reduction on the nanotubular surface was only similar to that of the SBAE reference. We hypothesise the underlying cause to be an effect of the surface morphology on the structure and composition of the saliva precoating that reduces its stability, giving rise to a self-cleaning effect. In addition, no negative influence on the osteogenic potential of the nanopitted surface could be determined by alkaline phosphatase activity, mineralization behaviour or gene expression; it remained on a par with the tissue culture plastic control. Thus, nanopitting seems to be a promising surface treatment candidate for dental implants to reduce infection related complications without compromising the implant integration.

The effect of different surface topographies of titanium implants on bacterial biofilm: a systematic review

“…zirconia, copper) [1,12,29]. Polished titanium surfaces had lower bacterial biofilm than untreated titanium with rougher surfaces [4,6,26,40,49,52]. The differences (p value) in the comparisons between the surfaces were not consistent in all of these studies (Table 1).…”

Bioadhesion in the oral cavity and approaches for biofilm management by surface modifications

“…100 nm were efficient in killing motile bacteria like P. aeruginosa, E. coli, or Bacillus subtilis [275]. In similar approaches, nanoscale structures were introduced onto different materials like alumina surfaces thereby limiting bacterial attachment [281][282][283]. Nanopores of 20-25 nm were introduced onto stainless steel by electrochemical etching [168].…”

Achievements in the Topographic Design of Commercial Titanium Dental Implants: Towards Anti-Peri-Implantitis Surfaces

“…The nanotubular geometry obtained by applying certain conditions in the anodization process has been demonstrated to promote the spreading, differentiation, and attachment of osteoblast cells [86]. In addition, the capacity of nanotubes (NTs) to reduce the colonization of bacteria has been reported, as the nanotopographic design favors osteoblasts versus bacteria adhesion to the surface because of the larger size of the cells [157]. In order to increase the bactericidal capacity of NT, many current researches are focused on the use of these structures as reservoirs of antibacterial agents for their in situ release in the implanted area.…”